I don't have any experience with this sort of bra
.......but I would imagine it could be removed with a heat gun, glue & tar remover & a lot of time & patience. Same with the bonnet stripes.
To save the protective bra, maybe you could cut round the stripes (very carefully), take them off & get a new set applied.
I would have a word with our resident Vinyl Maestro Phil at MINI PIRATE.com || 2008 || Mini Decals & Graphics
, I'm sure he'll be able to give some expert advice
Welcome to MINI2 by the way