This applies to the 06-08 M.
I have a Twilight Blue M and had the 3M film installed a year ago at 1000 miles. It is imperative to first call and visit to see the installers work!! I did not and I paid for it. 3M listed two "certified" installers and I chose the wrong dude.
It looked lousy. Had stretch marks all over, hood/fender lines didn't match up, the list goes on. However, I will applaud 3M as they hired an installer to completely redo the entire job UNDER WARRANTY! This speaks volumes for 3M for sure.
The guy showed up and did it in my garage yesterday and maaaaaaan does this look stellar now!
1. See their work in person first2. Make sure it is genuine 3M film(you know they'll stand behind it)3. Unless you decide to do your entire hood, request only the 3M kit.
Beyond the hood, fender corners, mirrors and front bumper(expect to pay about $1,200), 3M also has patterns for the M's front "A" pillars, the roof section in front of the sunroof, door edges AND for the top of the rear bumper.
I couldn't locate a 3M web site to see the kits but for reference you can go to
http://www.xpel.com, a competitor to 3M and their kits are similar. I noticed the xpel kit leaves two extra seams in the lower front fenders compared to 3M.
For those like CakeDaddy and I with dark cars, you may want to consider the whole hood if you can afford it.
A Q-Tip with alcohol will remove any build up of polishes, waxes, etc.
The only drawback, speaking for myself, is that it does leave an "orange-peel" look. The long-term benefits are well worth it.