Yeah, my dad let me buy rims back in February, but doesn't want me to do anything else. He's slowly getting comfortable with the idea of me lowering it, especially since I've started autocrossing. He controls my bank account, so I will have no choice but to get his permission before I get sways, shocks, and springs, but as soon as I do, the car will look great, and handle very nicely. I'm pretty sure he will let me, but if he doesn't, I'll have to wait until I turn 18 after I finish my Freshman year in college, so I can just bypass the enitre situation. I'm pretty sure he'll eventually let me do it...

As for your parents, just try and give them the impression that you aren't doing much, and you are using high quality parts. You are going to use high quality parts, aren't you?!