The bad news:
ClearGuard is hard to buy. I think that 3M must want it installed by professional detailers; it is mostly used to protect hoods and fenders against rock chips. Therefore, I told prospective vendors that I was NOT applying it in that fashion (which requires a fair amount of skill to look good) but using it just to protect high-wear areas on a fiberglass kayak and at strap contact points on my truck. The first time I bought it I found a detailing shop that let me buy some scrap pieces. The second time, I contacted the distributor for my region and bought a 10' x 6" strip for $30. That was the minimum amount required (which I didn't mind because the stuff is so useful). Your results may vary, so ask nicely and be prepared to shell out some dough.
I highly recommend this product for the 3rd purpose above.