i contacted the used dealer who had my m3 probably the day they got it. i was flying home from europe and spoke to them from heathrow. the next day i went to see the car and we agreed on price (it was already priced aggressively so that took 1 minute). then i picked up the car a couple of days later after they had done the initial service and cleaned it up.
that being said, we had looked at another m3 at the local bmw dealer that had been there all summer. nice car but no upgraded audio, plus a price that was stupid high..so it sat there. it eventually sold, but i have no idea when. i think dealers will often put a really high price on used cars to see if they can get someone to overpay, and with interest rates so low now their carry costs aren't that high...so they can sit for a while. when they get tired of playing games, they lower the price to the market and the car sells quickly at that point.
2015 M235i, MW/Bl, all packages
2012 x3 m sport, carbon black, prem, tech, conv, etc
evil the following 29'er, specialized carbon stumpjumper s works fsr, trek madone 5.2
nikon d500, d810, d750, 14-24, 24-70, 80-400vr, 500vr