[sweeps]

First congrats on paying off so much of your debt.

Can you be more specific about these "aggressive" and "very aggressive" stocks you've been investing in? 7-8% return is not that great if you're truly aggressively invested. Normally at age 30-35 you should have a portfolio along the lines of this:
25% large cap U.S. stocks
25% small cap U.S. stocks
25% international stocks
10% emerging markets
15% bonds and real estate

Also based on your projections, are you on target to meet your retirement needs? You don't mention how much you have saved for retirement, when you think you'll retire, and how much per year you anticipate you'll need in retirement. If you need to save more (I'm guessing the answer is yes), you can open a Roth IRA at a company such as Vanguard and Fidelity. After your car is paid off, you could direct that money towards your Roth (or bump up your 401k/403b contributions if that is a better option).

A common choice for your son's college fund is a 529 plan through your state. However, more information is needed because some 529 plans are good, some are bad. A Coverdell Savings Account is a possibility too. Or in some cases, a family is too far behind in saving for their retirement that they should just focus on that instead of saving for college. (As the saying goes, you can borrow for college, you can't borrow for your retirement.)