[thstone]

Unfortunately, you're not going to get much for $4,837.36 - including tires. A decent Boxster suspension upgrade will cost that much alone - without the tires.

A good custom cage will run $2000 to $4000 depending on what you want.

In reality, you're looking at $15K to $35K (not including the donor car) to build a real race car; depending on what you want, how competitive you want to be, and how nice you want it to look when you're done.

If you simply want a track day Boxster, then you're probably looking at something like $5K-$10K depending on what you want and how many compromises you're willing to make between street and track.