The new 2011 550i has a 4.4 liter V8 with twin turbo,thats pretty much the same engine in the 04-05 545, With out turbos,so im wondering if some tuner will come out with a turbo charger for a 545 someday ? P.S i know its not the same engine, but it is a 4.4 liter.

 

There are univesal kits that will fit the 545 now, also there are a few supercharger makers out there that I think have kits for the 545. Gitani maybe?