First off, I like your taste. I have wanted and M5 since the e39 version came out. I looked at those and then made the jump to an e60 2006 M5 mainly because it came with a warranty. I can't say anything bad about the car. It just wasn't what I needed in a vehicle and really couldn't justify the 500hp, 10 mpg, and jerky SMG transmission on my 10 minute drives to work. I think in the right situation it could be a great car and you could use some of the cars potential. For me, it wasn't. I ended up getting a 2008 550i that as all the same styling cues as the M5 but with a tiptronic 7 speed because I still like this model 5 series that other dislike. As far as the nuts and bolts on driving the car, the 500 hp and SMG transmission make the car seem like no straight road is long enough. You can double the speed limit in almost any situation. Handling is good but the car is VERY heavy. I would take the car with a manual that they made available in later years. The M5board is a good site for more information but it seems that they are interested in only getting more power out of the car. Like 500hp isn't enough?? Gas prices and the economy have caused havoc with resale on these cars. One of the reasons I got out of mine when I could. I would only buy one that is a CPO car and for a good price.
I think it is one of nicest looking 4 door sedans to date.