I looked at an M6 the other day. I like them a lot, but after I've had active cruise control on the 7 series, it's hard to go back to regular...(insert snobby remark here). When work is busy, I'll easily drive 100+ miles a day, so I'm looking for that "functional" fun car I can use as a DD. I think I've cancelled out the R8 for this reason...although I still love the looks and how it drives.
I still hold my Used Dealer's license, which I just use personally now. It enabled me to hold a dealer's open lot insurance policy for all of my vehicles, and not pay sales tax on any vehicle. The downside is I have to purchase my cars cash, as no bank will finance a business that breaks even on all its deals

and you it's hard to find anything that isn't "mainstream" as everything has been configured (and used) by someone else.
I will brag a little though and say that I bought my current 09 750i (msrp was $111,500) with 24k miles a year ago for 47,000. However, I did have to look for it for several months before finding that good of a deal. ...suppose it's the lesser of 2 evils. Use cash and not get hit with depreciation and sales tax. Or finance it, use cash elsewhere, and get dinged to death with depreciation and sales tax :/
...all this and I still don't know the direction I'm headed...other than it's time for a change.