Buy NEW if:
1. You take care of your cars well.
2. You put a lot of miles on it.
3. You intend to be in that car for at LEAST 10 years.
Buy USED if:
1. You feel any financial crunch in your life.
2. You don't put a lot of miles on it.
3. You could foresee a life-changing event (different/loss of job, marriage/kids) in the next 5 years.
1. You've got the money.
2. You don't have the time.
3. You think you'll want a different car in 3 years time.
I'm 35 years old and I've never had a new car.
I'm not a fan of quickly depreciating assets either. Use Facebook, tell your world you are looking to find a car to drive, can be used. Often friends are willing to unload their current car at a more-than-fair price because they NEED a new car (job situation or life situation). When I bought my home, I bought it from a friend's aunt. I got a full disclosure on the ups/downs to the home and we saved 3% with me not getting a real-estate agent.
When we had our daughter 3 years ago, we bought our first new car (for my wife). My wife has USAA afiliation (through her dad) and they have discounted rates - which are pretty-much no-haggle. We used consumerreports.org to select our vehicle.
Regardless of buying New or Used, I'd suggest going to this site and reading EVERYTHING.
You'll be prepared if you do... and spending money on their guides for the car that interest you are well worth the money.
It's not the cleanest website in the world, but I read almost everything on there before buying our vehicle and felt very comfortable about the auto-buying industry after I had read so much.