Reddit mentions of Lemon-Aid New and Used Cars and Trucks 1990-2015

Anxiety, is a killer. I think you need to think of a couple of things.
How much is the used car going to cost on year to year basis to run?
Can you make spread sheet?
How much are you going to have to spend annually on repairs, which will increase over time.
At what point does cost running+repair+down time+anxiety over car failure make you want/need to buy a new car?
Avoid rust and people that will not let you take car to garage.
In my opinion i would put the 5K as down payment and by the car, new cars these days are much better made, last longer, more fuel efficient and have better warranties than before and certainly better than used cars.
For me the reason would be you level of anxiety which ought to be reduced by knowing you have warranty and new safety features.
If you want to read more about cars go to places like: Edmundtons etc.
If you want to read best book on used and new cars then read
Phil Edmonston's Lemon Aid Used Car and Trucks
they come out every year, your library might have it, idk where you live,
here is amazon listing

http://www.amazon.ca/Lemon-Aid-Used-Cars-Trucks-1990%2520132015/dp/1459719409/ref=sr_1_1?ie=UTF8&qid=1412181376&sr=8-1&keywords=lemon+aid+car+guide+2014

Just my two cents. good luck.