Just thought of this:
There should be an online game mode similar to the SP pursuits of Most Wanted and Carbon. The game would end when all racers are busted, the police call off the chase or time runs out. No finish line, and you could specify the time limit when searching for a game. It could be anywhere from a five minute time limit to two hours or even unlimited (and in that case, the only way for the game to end would be if the police would call off the chase, or every racer was busted).
You could squad up with some friends and all be police while you try to bust a few racers or vice versa. To fill in the numbers, each cop could be in control of a 'squad' of A.I police cars, and swap between them. This would be like in High Stakes. The cars you weren't driving were being controlled by A.I.
This way you could have one cop and his 'squad' trailing one of the suspects while you get the other cop and his squad to intercept them with a roadblock a few klicks up the road.
You could even have clans (Syndicates? Precincts?) where you get points for evading and busting. Each clan would have a Wanted Ranking and a Police Ranking. The Wanted Ranking would be calculated by the amount of evades and race wins while the Police Ranking would be calculated by amount of Busts. You could even have clan battles where one Syndicate would play racers and another one would be the cops. Syndicate Battles would have more risk so you'll gain or lose more points on your Wanted/Police Ranking compared to random public matches.