Personally, I wouldn't go with a used german car (especially VAG products) unless it's a CPO or it's new.
One idea is to go with a plug-in hybrid and before you guys lynch me, here is why. The tax rebate is going to be increased to $10k (if it passed) and a Volt is eligible for the whole $10k (double of last year eligibility).
My idea is to lease one for the same amount of time the warranty which means you don't have to worry about repairs. Plus, there are GM mechanics on this board (Cordell is one) of whom you can give your choice words if there is something wrong with your Volt.
Upfront cost is roughly $5k and the $4+k can be used to pay for roughly a quarter of to half of the lease payments. Fuel cost (electric and gasoline) is very low especially if you can plug it in to your neighbor's house or your work.
A full charge supposedly costs $1.51 in electricity (good for GM claim of 40 miles) which, depending on the 87-octane price, means roughly half a gallon of gasoline. That calculated to an equivalence of 80 miles per gallon of gasoline, cost-wise. The car will never run out of "juice" (electricity or gasoline) as long as there is a fuel station nearby.
There I said it, you guys can ban me now