car modding certainly hasn't died down at all. that culture is alive and well i assure you.
why EA refuses to do another Underground game, I really don't know. the fact that EA greenlit and released the abysmal NFS: The Run but won't make another Underground game is even more upsetting. as much as I loved some of the more recent NFS games, the Hot Pursuit formula is getting stale.
it'd definitely be refreshing if EA took the franchise to a fictional city that'd support a more versatile racing formula. bringing back the drag races, drifting and classic circuit racing would be great, especially if cops were added this time around to the circuit races. making cops playable would also be a good thing to keep. couple that with the All-Drive feature that Rivals added and the multiplayer for a new Underground/Rivals hybrid would be huge; customized cars, cops, lots of racing modes and a city to play in would be a great direction for the series to take.
speaking of NFS: The Run, that game definitely teased us with this pre-order bonus lol.