Look in to buying a car rental shop/city lease return. They usually have an insanely fantastic maintenance regimen, the big depreciation is already absorbed and any weird kinks are worked out.
As you say, you are young. In my opinion, you should not be avoiding car payments at all. Illustrating that you can responsibly handle debt, and still maintaining a rigorous savings routine will turn you into a financial sweetheart at lending institutions.
"He's done very, very well with a $40K loan amortized over 6 years at 9%" With your savings, suddenly you have amazing leverage to secure a good rate on a $400K loan for a house in a few years. Now we are talking a loan where a percentage point amounts to huge dollars, EVERY YEAR.
Think of it as a type of loss leader, or priming your financial pump.
You should look into good v bad debt. Don't avoid debt, you're shooting yourself in the foot. Straight savings is leaving money on the table, and its security maybe shouldn't be on your top 5 list of priorities.
I'm a Canuck, so I don't know about the US. Student loans are pretty good debt. Usually low interest, and the interest is tax deductible anyway. I think that should be at the very bottom of your priority list from the sounds of it. A physics prof I know put it super well "Always take as long as you possibly can to pay a debt", especially low interest ones that are tax shelters!