First as someone stated above, pay off the highest interest first.
This is the option we have been using for a number of years and it works out well. Buy a program car through a dealer. Someone else pays the first years depreciation and you end up with a nearly new vehicle and a full warranty. If you have money earning 4% and can get a loan at 2.5% take the loan and leave your investment were it is. You will be saving 1.5%. Pay it off in a year if possible. Sometimes they will penalize you for paying it off sooner. If your credit is excellent you can be offered very low interest on a loan. Buy the vehicle when new car sales are slow. Not all dealers will make the effort to find the vehicle you want so find one that will and stick with them if they treat you right.
By going with a program car you can end up with a lot more vehicle than you were willing to spend on a lesser vehicle. It has worked this way every time for us. We now call the dealer and let them know what we are looking for and about how many miles we would like on it. May take a month or two to find. He sends us photos and if we say it's a go he purchases the vehicle. We have had 5 of these now and it has worked great. The last one had 8,000 miles on it and belonged to a factory rep.
Good luck with your purchase.