Originally Posted by Ubetit

I think you might be starting to get it but I still see a shimmer of hope:

1. No dealer hands you $15k cash "incentives"
2. I don't know what you paid for your car but you still owe 36 payments on your current car. Even if they gave you $30k on your car as trade, you/they still need to pay off 42.8% of your original loan.
3. You won't get $30k for your car, sorry. I just searched autotrader for all of Canada. There are twenty eight (28) 2009 370Zs for sale and only 1 is over $30k (a private seller even). The dealer would have trouble selling your car at $30k retail. He'll give you $22-24K if you are lucky realizing they want about $4k out of a used car.

When it's all done and said my original estimate of what you'll need to finance a GTR stands.

Keep your current loan and car. Make any extra payments to a savings account. When that savings account amount matches the loan payoff, pay it off. Others will tell you to refinance a shorter term and decreased interest which is also fine as long as your budget can take it and you are pretty sure of your employment for at least the life of the loan.