Ponder this grasshopper;
If you buy a house for $175,000 @ 6% the total interest you will have paid at the end of the loan would be $202,716.
If you add $25,000 to pay off a car and borrow $200,000 (depending if the house would appraise for $25K over selling price) @6% the total interest paid at the endof the loan is $231,676.
You will pay $28,960 more in interest to pay off a $25,000 car. Basically you would pay double for the car.
If you kept the auto loan for 60 months at 10% (an astronimical rate but you are 22 years old) the total interest paid would be $6,870 or $22,090 less in interest.
PS Mortgage companies and banks have rules that keep people from screwing up too badly. I doubt you could do it.