Hi,
It sounds like you borrowed 13500 over the full life of your mortgage.
Generally when you refinance a high interest rate loan into your mortgage, you should ask them to allow you to pay off that part of the mortgage over a shorter period. Otherwise you end up paying for your car 20 years after you bought it.
In your position I'd advise a few things.
1. If you have extra cash, and you have no other debts,
and your SSIA's are maxed out then putting it towards
your mortgage is a good idea. Either in lump sums or
ask to have your repayments increased.
2. If you are happy with your current car, do not buy a
new one. It never makes sense. Try to save up a bit
so you can buy your next car for cash.
The best way (i think) to handle cars is buy a 1 or 2 year old
car for cash and then drive it for as long as possible.
-Rd