Piston Slap: My Mistress' Eyes Are Nothing Like the Sun Edition

Sajeev Mehta
by Sajeev Mehta

Michael writes:

Hello Sajeev, I’d like to ping your automotive wisdom with the following question. Soon I’ll be looking for a new car to replace my leased Corolla. I love power moonroofs (which my Corolla also has). My next car will be a long-term keeper, and even though I’d love to equip it with a roof orifice, I’m not sure about the longer-term reliability of power moonroofs. Are they known to start leaking, to require expensive repairs? Or is it better to buy a car without a moonroof and then have a manual sunroof installed; and would it void the car’s warranty?

I’d like to keep my next car until it falls apart — 10 years or longer. Thanks muchly for your time.

Sajeev answers:

Take it from the guy who has two 10+ year old cars with glass tops: do it. After thirteen years, one car’s factory moonroof needed nothing but a new rubber gasket to eliminate wind noise, a $50 part from a company called the Sunroof Doctor. If you’re paranoid or OCD, ehow.com has some helpful hints on sunroof maintenance.

The other option is a Webasto unit installed at the dealer, and it only needs a new felt pad to silence an occasional rattle from the pop-up wind deflector. No motor failures. No leaks. No brainer.

I prefer factory installed moonroofs because they have a better-integrated look inside the car, especially the switch and bezel. Most importantly, their unique roof stamping lets the glass sit flush with the roof: aftermarket parts normally sit a millimeter on top as they are a cut the roof and drop-in affair.

Bonus! A Piston Slap Nugget of Wisdom:

If you find a great deal on a roof-less car, go aftermarket and haggle on the price. Dealers usually have an off-site outfitter who sells their services at a discount: either you fight for dealer’s cost, or go to the horse’s mouth instead. From what I’ve seen, there’s a 10% markup on this service, so negotiate a better deal.

[Send your technical queries to mehta@ttac.com]

Sajeev Mehta
Sajeev Mehta

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2 of 25 comments
  • MBella MBella on Jun 17, 2009

    Factory hands down. The only serious problem you have to worry about is the drain hoses. They shouldn't be a problem if you keep debris from clogging them. Then things like seal will keap the noise down.

  • JohnHowardOxley JohnHowardOxley on Jun 17, 2009

    My dislike of sun/moon/star roofs [added mechanical complexity, more weight high up in the car] is sufficiently great that when I was considering purchase of an S5 [which is a great car in my book, otherwise], the fact that a s/m/s roof was a mandatory option was the deal-breaker. When I look upwards while seated in my car, I want to see solid tin!

  • Lorenzo All the efforts made over decades to reduce/eliminate NVH in ICE cars, and now they're putting noise and vibration into electric cars. It reminds me of efforts to make veggie burgers taste like meat. Vegetarians don't want the taste of meat, and meat eaters will want meat, not veggie burgers.
  • Jalop1991 A true golf cart.Sure, it's a penalty box inside. But you're not in it for more than a few minutes at a time during commutes and in between charging stops.Ergo, it's the perfect...golf cart.
  • Zipper69 I'm sure it will sell just fine at all trim levels.I'd only note that IMHO the dashboard is a bit of a busy mess.
  • MaintenanceCosts Why do you have to accept two fewer cylinders in your gas engine to get an electric motor? (This question also applies to the CX-90.)
  • Zipper69 Do they have unique technology that might interest another manufacturer?