How to Buy a Used Car - Pt. 3: Due Diligence (The Inspection)

Steven Lang
by Steven Lang
how to buy a used car pt 3 due diligence the inspection

[Ed: Part one of Steve Lang’s updated used car buying guide is here, part two is here.]

You can rigorously apply the tests described by previous installments of this series without encountering a single setback. However when it comes to buying a used car it pays to assume one simple salient fact: you don’t know the complete truth. At least not yet.

When it comes to pursuing the deeper truths about a used car an experienced mechanic will inevitably become your greatest ally and advocate. For most consumers finding a knowledgeable mechanic will be the most important step in the used car buying process.

Before we talk about that, I want to be perfectly clear on this point. A used car is guilty until proven innocent. Do not buy one without taking the car for a professional inspection. If the seller doesn’t agree to let you do so you’re done. Period. No exceptions. Ever.

Now mechanics tend to divide into three categories: the shade-tree, the Nazi and the diligent professional.

Shade-tree mechanics are hobbyists on limited budgets. Due to the lack of equipment (or experience), they may not be familiar with the unique wear issues and maintenance needs for your vehicle. The shade-tree mechanic will look at the car’s basics, take it for a short test drive and call it good (or “not bad”).

The Nazi will attempt to perform every mechanical test known to wrenchkind. Submit the car to a standard of inspection that is rooted in la-la land. Then make you financially fearful of buying anything other than (cough! cough!) one of their vehicles.

Obviously the Nazi is a non-starter. Often times these party members will work for dealerships (but not always), and are therefore pre-occupied with meeting their service department’s monthly quota of service hours and revenue.

Unless your next car has a prancing horse or bull at the front of it, you’re usually far better off with a diligent mechanic. The diligent mechanic will work through a standard check list and then take the car for a test drive in a variety of operating conditions.

Diligent mechanics are experienced independent professionals with established roots in your community. To find one I strongly recommend visiting the Mechan-X files at

I also can’t over-emphasize the importance of personal recommendations; especially from people who own the same model of car you’re considering buying. Many small to medium-sized repair shops will post testimonials on their “ego wall.” Read them carefully.

Before the inspection takes place, collate the list of the concerns you created during the test drive. When you deliver the car for inspection, go over them with the mechanic one-by-one. Make sure you both have a clear understanding of all your potential concerns. This will provide a base line for the inspection to follow.

Some mechanics inspect used cars for a set fee. Others charge an hourly rate. In both cases, the post-list discussion should conclude with a confirmation of the probable inspection cost. Leave some leeway; you don’t want the mechanic to stop their investigations for the sake of a few bucks. (Leave your contact number for this possibility.)

The best way to build a healthy relationship with any mechanic is to simply try not to be one of “those” customers. Just let them get on with their job. Don’t stare at the mechanic while they’re doing the inspection. In fact it’s best to leave the premises entirely. And don’t phone your mechanic two hours later and ask for a status report; wait for their call.

Once the inspection is completed, sit down for a one-on-one debrief with the mechanic who made the inspection (even if you have to come back on another day). I always prefer to speak with the actual mechanic or at least have them in attendance with the “service advisor.”

Let the mechanic speak without interruption. Some diligent mechanics will go on for quite some time; some will simply say “here’s my report.” Either way review the information and let him explain every issue and potential issue to you. After they’re finished, don’t be afraid to say “I don’t have a clue what you’re talking about” or “Is this a sign of normal wear or abuse?”

Make your own list of trouble spots from this conversation. Note down the potential cost to repair and whether or not the issue is urgent or eventual.

Once you’re finished the play-by-play, ask a few general questions. I always ask “Did the owner do a good job maintaining this vehicle?” and “Did the owner use good parts or cheap parts?” Either of these inquiries usually invites a deeper insight with the mechanic.

If the used car has survived the inspection process without revealing any critical issues to your diligent mechanic, it’s time for the final negotiation with the owner.

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4 of 45 comments
  • Dvp cars Dvp cars on Aug 03, 2011

    can't believe the anti-domestic, pro-asian ranting on this subject. Has anyone been to a Toyota/Honda store lately? What do you think those 20 overall-clad fellows in the back do all day? And they deal mainly with nearly new vehicles.

    • Redmondjp Redmondjp on Aug 04, 2011

      +1 I have owned a couple of dozen American cars but currently have a 1997 Civic (mine) and 2001 Odyssey (hers) as daily drivers. Let's see, the Odyssey is on it's THIRD automatic transmission at just over 100K miles, and my Civic drinks more oil than any car that I have ever owned (a quart every 200-400 miles). None of my American cars ever had either of those problems. The people who think that Hondas and Toyotas are perfect cars dropped right out of heaven need to wake up and smell the coffee! If you REALLY want to know what cars are good/bad, talk to any mechanic and ask them what to buy, or what NOT to buy. My 1988 Buick Electra T-Type (owned for 16 years, sold it still running and driving just fine at 221K miles) was the best car that I have ever owned. Original engine and tranny. Original exhaust system all the way back to the tailpipe. Original axle shafts, with the first CV boot splitting at 212K miles (sold it that way). Find me ANY 1988 Honda Accord with over 200K miles that still has its original axles or exhaust system. And with my Buick, I didn't have to do the timing belt every 60K which saved me a couple grand in maintenance costs. Yes, I had the crappy peeling GM paint and a rattly interior. Face it, every car maker makes some stellar cars, and some not so much. Just closing your eyes and buying a Toyonda doesn't guarantee perfection.

  • NN NN on Aug 04, 2011

    This advice is great if you are buying a car locally. If you are buying a car at auction then you don't have such an option and you're taking a larger risk. My take is that Mr. Lang would simply not recommend people to buy from auctions, though he does it himself and I'm sure doesn't have the option of doing such a thorough check on everything he buys. The reality is, this is how tens of thousands of car transactions are completed, on eBay or at local auctions. I like the $2000 rule (add $2000 to what you pay for potential unseen expenses), however, as we know a major repair can cost more.

    • Aristurtle Aristurtle on Aug 04, 2011

      Buying at an auction is a bit more of a gamble, which is why the price will typically be a bit lower.

  • Jeff S I haven't seen one of these since the 90s. Good find.
  • William Piper Ditch the Renault-Nissan-Mitsubishi Alliance for starters….Mitzu has probably benefited less than the other two partners and it has shackled any brand creativity moving forward.
  • Tassos I knew a woman in the area, a journalist (at least she claimed to be a reporter of some kind) who owned one of these tiny pickups with a manual transmission. SHe was only 40 at the time, but she must have been hard of hearing, because she would routinely forget to shift and we would go at fairly high speeds in very low gear, which made a huge racket, which did not seem to bother her (hence my deafness hypothesis). Either that, or she was a lousy driver. Oh well, another very forgettable, silly car from the 80s (and if my first and LAST VW, a 1975 Dasher wagon, was any indication, a very unreliable one too!)
  • Tassos Now as for the Z specifically, Car and Driver had a comparison test of the new Z400, a car that looks good on paper, with plenty of HP etc, but, despite the fact that the cars that win in those tests are usually brand new models that are more up to date than their aging rivals, the Z finished DEAD LAST in the test, to my ovbious surprise.
  • Arthur Dailey Sorry but compare that spartan interior to the Marks that Corey is writing about. 'A cigarette lighter'. Every Mark had 4 cigarette lighters and ashtrays. And these came standard with 'a 3.4-liter, 182-horsepower straight-six in the engine compartment and a five-speed manual transmission'. Those do not tick off many of the luxury boxes aspired to by 'the greatest generation'.Not sure about the 7 series but one of My Old Man's associates showed up once with a brand new 5 series circa 1977 and they gave him such a bad time that he traded it for a Fleetwood within a week.