Having watched them, and witnessed the tools required (Heat gun, Squeedgee, Scalpal) .. If I had a flat surface to do , ie bonnet or roof I'd have a go myself - The Z4 Coupe roof is curved across the entire surface, making it a right PITA - E36 would be a piece of pi*ss tho, bonnets, spoilers etc you'd be done in an hour.
The material is quite remarkable, you get it warm, peal off the back (its self adhesive) and apply a small area, using a squeedgee type of thing to push the bubbles out, you then warm the remainder with heat torch (hairdryer -DIY !!)) and it has a memory and returns dead straight..... Reminded me a bit of window tinting film.
I pinched two bits that where destined for the waste bin and I'll be DIY'ing my front grilles with a hairdryer and scalpal - watch this space , I'll post up a guide !