The $5,200 you invested is not "bad." However, it is not optimal. People here are saying you need to invest money in an order. The order is this:
1. 401k - BUT ONLY UP TO THE MATCH.
2. Student Loan at 6.8% Interest.
3. Roth IRA up to the limit ($5,500)
4. Car Loan at 2%
5. 401K up to the Maximum individual contribution ($17,500 in 2014.$18,000 2015)
6. After Tax Investments (where you currently have the $5,200)
Please understand the order is not set in stone. But is it clear your $5,200 is being invested way out of order.
The other issue being debated is your car loan and which order your car loan should be paid off. Some might put the car debt as the absolute lowest priority (i.e. #6 in the order) because your interest rate is low. Others are saying you should sell the car because that will eliminate the debt immediately. I have put the car loan at number 4 because that is my opinion - IF YOU KEEP THE CAR.
IF YOU SELL THE CAR, you would, theoretically, move more quickly on the "order of investing" by eliminating the car debt. Eliminating the car debt would have two benefits. One, you now have less debt to pay. Two, you have $300 in monthly cash flow to invest. But, this only works if you can use the proceeds to purchase a vehicle that fits your needs or stop using a car altogether.
Part of the unwritten assumption of the other posters, is that you lost big money buying a new car. It is unwritten because buying a new car is considered a rookie mistake on this blog. You likely need to accept that you made a bad decision on the car and simply do your best to salvage what you can. "Salvaging" might be keeping the car, paying the debt, driving the car for 10+ years and knowing you bought something really expensive and unnecessary OR "salvaging" might mean selling, eating a loss and buying a cheaper car cash (but eliminating the debt.)
By the way, I am not trying to be a jerk by saying that purchasing a new car is a rookie mistake. I can tell you from my personal experience that you are not alone in making a bad car decision. I once bought a (used) Lincoln Navigator in cash but then sold it 6 months later after I found this blog and realized my error. So, don't be too hard on yourself - at least you didn't buy a Navigator :)