Yeah, thats what your dad needs to do, when I bought my '99 Eclipse my senior year (99, hehe) my dad was insured on the mitsubishi, and I was insured on an old farm truck we had. Other than that, I don't know what to tell you, $500 a month has to be full coverage even for a 17yo, I have tickets, under 25, ect. (But am married) and full coverage for a SC400 is a fraction of that.
Ohh, and have you taken drivers ed. Must have.