You can make use of all sorts of different vehicles, but of course you'll have to unlock them first. To do that, you need to complete missions around the city (which isn't open for exploring - you always have to follow the road signs).
Still, during the missions you have to be careful not to crash into oncoming traffic. Luckily, the cars you use have turbo power, which can help you make up some time on straightaways.
Police Supercars Racing is a fun, original racing game with great graphics. Not only is it an excellent title, but it's totally free.