E60 M5 and E61 M5 Touring Discussion
I picked up a used 2008 E60 M5 (~40K miles/Interlagos Blue color) a few months back. I traded in my good ole 2006 E46 M3 for it.
I was wondering what are the first few things or most common things to upgrade? I've read about the RPI ram air stuff and/or maybe a chip upgrade. Are the K&N...