If I can give you one bit of advice, it would be this: learn to be content with going slow.
I know it's hard, maybe impossible when you're still 17. When I was 17 I was trying to make my Dodge Neon fast. I spent way too much money on it, and yeah, I had fun making it mine....but the car never was actually fast, and if I could have that $6-$7K back.....boy oh boy.
I admit, I do still have a dodge neon to play with, and it is fast. But I'm content going slow in my 4Runner, because I know without spending 4 digit money, I'm not going to make it THAT much faster or more powerful. Better to make it reliable, and keep up on the maintenance. Just my .02. :hatsoff: