I need to raise my bounrty from 614000 to 790000 and it is taking me forever...

I've always gotten the excessive speeding infraction at around 200 mph and the reckless driving infraction at around 220 mph.

I also recommend the Lamborghini Gallardo as a good pursuit car, it pushes through roadblocks quite nicely and doesn't have too much of a problem reaching those speeds once modified. If you get Ming's pink slip, his is nicely modified, just add ultimate nitrous.

I don't know what everyone else does, but to raise my bounty with a good chance of escape this is what I do. First get into a pursuit...obviously. If you don't have a high heat level yet, just make sure you don't lose him (or immobilize it) and start crashing into everything from newspaper stands to other vehicles (DON'T HIT BIG RIGS, they stop you dead in your tracks) to build up your heat level. Once you have a decent amount of squad cars following you, say about 3-5, get on the freeway and just keep up the pursuit until road blocks start goin up. Just keep followin the freeway around the city. At the point of the Freeway where it makes two loops and you can choose which one to get on, slow down. It's easy to lose the cops in that area, just make sure they can keep an eye on you. Periodically glance at your radar for 1) road blocks or 2) the F@#$*N SUV's that just Kamikazee you. Once you see either of those hit the time breaker and position yourself to take out squad cars. Immobilizing squad cars is the fastest way for me to raise bounty. Anyways, once you're close to or at your desired bounty exit the freeway, hit as many pursuit breakers as fast as you can and hide under something because chances are that the helicopter's after you too. Hope this helped.