Bought Free Riders today! Playing tonight, impressions tomorrow. w00t.
It seems that a lot of the SEGA references from the previous games were cut, probably to separate Free Riders from the all-encompassing All-Star series. No Crazy Taxi, Opa Opa, SC5, Nights, etc. Then again, all of those are in SASASR. Thank god the Hang-On bikes remain, and there are references to past Riders games (Metal City from SR1, the previous theme songs). Also, it's nice that they added Vector and Metal Sonic to the series.