I have used both 3M product and Ventureshield (now owned by 3M). The 3M product is a little thinner and easier for a less experienced installer to install around severe corners. It also has a more obvious "orange peel" texture. Ventureshield is a little thicker and much less orange peel. In the hands of a good installer, Ventureshield, is the way to go in my opinion. I have it on 3 cars and would recommend to anyone.

As mentioned above, car needs to be carefully cleaned/detailed before application and make sure using professional installer. A good installer will "wrap" the edges where possible so you cant see the edge. I have seen entire cars wrapped in this stuff and depending on the color of the car, it is barely noticeable and provides excellent protection. Nice thing too, if it ever gets damaged, it can be removed and replaced easily without any underlying paint damage.

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09 E70 35d (Space Gray/Tobacco)
08 Audi RS4 Cabrio (Sprint Blue/Silver)
2010 Audi R8 V10 (Velvet Purple/Black-White)