I am writing this proposal to this you this that $30 won't cut it. I am speaking to you like this is because I have done creating a game before (you can have a look in my portfolio under the name THAT SUMMER WE MET) It took me 2 years to complete that game that could be use in a real life situation which is happening right now in Thailand, and I spend more than $500 on that project. Although I do all the programming, research, and I even write my own story to cut some of the costs. The art is one thing but the programming part is a big gigantic pain in the ass (although i had used a platform to create this game, it is still a pain in the ass). But that how big the project was, and it just 2D.
First you have to tell in your description that how big of a racing game that you want it to be? Is it like CSR that contain loads of cool cars (with nitro) and with different stages and settings. Anyway, all I wanted to say is that your budget is wayyyyyyyyyyyyyy too low. But it is also depend how big is the project.