I promise you its worth a lot!
Interesting idea to be able to choose a front that fits your style. It's true that the grille is a part of the bumper so it could easily be done. I'll think about it when I start my car company :-)
And here is a mix of the Ferrari and the BMW. Being a Swede I can't help thinking about the Volvo Amazon (think it was called 121 in the UK). I also prefer the original sills, fits the wide fenders.
Ferrari-BMW front.jpg