A prius with a minigun integrated with the roof. No need to outrun cars and choppers if you just make them inoperable. Can do 60 mpg easily when not evading at 70 mph, 40 when you need to go faster at a steady ~90 mph. And if you need top speed, it can do like 125, though of course economy plummets. Conservatively, at 10 gallons, you could do double the range of any other average car, so once you are free and clear, you can make lots of distance in not a ton of time. Get to the switch point, disassemble and take the minigun, destroy the car, and use car #2 for blending back into boring suburbia - anything will do.

No I will not answer any questions on how I got this data.