Without getting into the technical specifics of each, Ceramic is the latest and greatest as of the last few years, approx 5. It also has a little more clarity, much more durable and most importantly blocks more of the UV but no difference at all relative to interference with nav, sat, etc.
However there is a big difference in cost. The ceramic is at least $100 to $125 more per vehicle at least thats the price difference here in So Cal from a great shop I have been using for years and someone I trust thoroughly who is also giving me a great price.
Personally I have had both. I have an MB E500 with metallic and then my 2010 A6 with Ceramic, The ceramic looks better and hands down blocks the heat moreso. If you have the extra money to spend go with ceramic. If you dont, then you'll be fine with standard film thats been used for years.

Originally Posted by
BigBen
Normally metallic for tint. It's going to be a $50 difference in cost for me. It seems like a no brainer for that amount of money but my wife's car will be getting the standard metallic tint.
Bookmarks