I have a 545 and came across some wheels that I like but they are from an E60 M5.
The size and offset = front 20x9.5 /5mm rear 20x10.5/25mm

The current tire sizes are = Front 255/35/20 Rear 20x10.5 285/30/20

So my question is...will this fit on a 545 or what will I need to make it work. I already know the front tire size is too wide, I will need a 245, or should I just skip it and find something else.

 

The rear setup will work fine however the front setup will be tight if it fits. For sure the 255/35/20 is too wide and a tad too tall. On my setup I am running a 20x9 et10 up front with a 245/30r20 tire which fits just right with no rubbing. I was running a 255 up front but it would rub the fenders all the time even with my fenders rolled. IMO I'd probably skip these wheels and find ones that have a better fitment up front.