is forza 4 still acative enough to be worth spending more time in? auction mainly.
Forza 4 is still active especially if you like league racing.
Check out the Racers Lounge.
Dude, check this out - currently 27 drivers signed up for this sponsored series, with prizes, that starts tomorrow night:
http://forums.forza.net/turn10_postst5955_StopDropGaming-com-KitSound-Cup---Sponsor-Confirmed.aspx
League racing sounds like fun, unfortunately I do not have the time to become good enough to race seriously.
As far as the Auction House goes, I think you could describe it as “fairly” active, since many of the serious tuners and painters have moved to Forza 5. Personally, I don’t participate in the AH much. I find the cars overpriced and am concerned about getting involved with illegal or modded vehicles. I’m sure there are deals to be had, but I spend my limited gaming time actually playing the game.