Smart Car of America Forum banner

roof cracks

3490 Views 11 Replies 8 Participants Last post by  MikeB1
i don't have them yet but i was reading about how uv causes it. in is really uv or could it just be the heat then you get inside and turn the a/c on full blast?

if it is the uv them what about Rejex (i guess that's the best uv blocker on the market) or is there any wax with a higher uv index.

and then if the cracks get unsightly what about either painting the roof or having a wrap made for it. again i have no idea how well a wrap holds up (does anyone have an idea which is cheaper?)

the previous owner tinted the roof and i installed a sunshade to block the radiant heat so i can't see if i have cracks or not

i am just thinking and planning ahead
1 - 1 of 12 Posts
My 2012's roof survived 60,000 miles before crazing. But once it started crazing? Oh boy it spread extremely quickly.

Unfortunately, no cause or prevention were found. Through some research, many of us were able to pull spec sheets for the Makrolon and they were pretty pathetic. Here are a few of my favourites (those links are dead nowadays):

- The roof's protective coatings start getting damaged at and above 150 degrees and are accelerated when moisture is introduced at the same time.

150 degrees is scary. If you park your car outside on an average summer day the interior can reach temperatures of 180 degrees. And all closing the shade does is focus the heat harder onto the roof.

One of the more popular mods in 2008-2009 was cutting one of those shiny reflective windscreen sun shields to fit into the roof to reduce interior heat. Well, a couple years down the road quite a few of those cars ended up being the worst examples of crazing. All the heat of the beating sun getting reflected into the weak roof.

- You cannot clean the roof with ammonia and spot free rinses are also bad.

- There was an entire list of good and bad chemicals, somehow Bayer expected you to know exactly what chemicals your local car wash uses.

Many of us complained, tried calling Bayer, just about every trick in the book (that you can see repeated in the 453 fuel tank thread), ultimately the answer was effectively "after warranty you're on your own". They never admitted to fitting smarts with a product unfit to be on a car.

Indeed, smart claimed to have fixed the issue in the 2013 Model Year. Eventually reports of crazing began tapering off, and then we collectively as a forum began looking at new interests like the ED and the 453 concepts. Did they actually fix the issue in 2013? I guess so, but that's only because I haven't seen any reports of a 2013 crazing yet. :)

I believe my car made it so long without crazing because I never closed the sun shade and was careful to avoid spot free rinses whenever possible.
See less See more
  • Like
Reactions: 3
1 - 1 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.