I currently own an E60 M5 but I'm looking to move it on soon and get something else. I seem to be stuck on the f10 M5 and e63 biturbo (circa £25k), but can't seem to think of anything else worth having that has better performance than the e60. Anything I get won't have a warranty and will end up tuned as more power is king. I had considered supercharging the e60 but I don't think it is the right idea. Any thoughts?