I waited 6 months on my M3 before I got VentureShield and wish I had done it sooner. BMW uses such soft paint that after those 6 months it looked like my previous car did after 18! Definitely worth it IMHO. Hood might not be necessary on the M5 since unlike other BMWs, the hood doesn't dip down toward the front of the car because the front bumper panel rises so high, but definitely get the front bumper, mirrors, and headlights done.
'16 Cayman GT4 (delivery pics
Gone but not forgotten:
'11.75 M3 E92 Le Mans | Black Nov w/ Alum | 6MT (owned 5/2011 - 11/2015)