I had a 2003 540i M Sport in 9.5/10 condition and FULL regularly scheduled maintenance records. Not the cute little ‘m sport’ that everyone claims to be the real deal, but the M Sport with the GF vin number, 6-speed manual, full factory installed M goodies... BMW NA made these for only one year, 2003, and only imported around 1100 to Canada AND the US - combined. They were a special order through the dealerships. Production numbers are far less than the e39 M5...but guess what? No M badge, no exclusivity. No exclusivity, no demand. No demand, no retention or increase in perceived value.

The 4.6is and 4.8is are super trucks, but I wouldn’t consider one an investment. Of course, I don’t think you would lose any value in buying one. I personally think the depreciation has hit its bottom, but this is just my personal opinion. If you want to make an investment, you can’t go wrong with an e39 M5 or e36 M3 right now. BaT has pretty much ruined reasonable prices for the e28 M5 and e30 M3.