I am in no way a financial consultant. I can only give you hypothetical advice and would strongly advise you to seek the counsel of a loan consultant or financial planner/advisor.
That being said:
Your situation is a delicate one and it comes down to a matter of priorities. Loans are tricky, and I'm hesitant to give you advice without knowing the parameters of the loan agreement (what is the auto loan term - years, months?). For instance, let's say if you have a 10.69 interest rate on a $20,000 car loan and the auto loan term is 4 years or 48 months. This means that your monthly payments on the truck loan should be around $513.00. If you continue to pay this for four years, you will have the loan paid off with about $4,500 dollars interest ($513.00 x 48 months = $24,667) .
So, if you kept up with your monthly payments of $513.00 without touching your ING account, at the end of your 4 years, you will end up paying a total of $24,667.00.
Now, I do not know about your personal finances, but a monthly payment of $513 can be a little steep. If you choose to pay less than that, it could cost you a lot more in the long run. For instance, if you decide to pay the minimum monthly payment allowed on the loan, you could be paying off that truck for many years. Like, I said, it comes down to a matter of priorities and you should figure out how much you can afford a month on the truck while still being able to save for your monthly budget, and a future house.
I hope that this helps a little. Remember, this is in no way financial advice. I highly recommend that you seek out a financial advisor to help you with your situation.
Take care.