If you have a car that runs reliably, don't waste money buying a new one. In PA, we have 6% sales tax. So you buy a $45,000 car and get $10,000 on a trade-in, you will pay the tax on $35,000 or $2100. That tax gets you nothing. But put it into replacement parts on your existing car, you can probably extend its life by at least several years if not more. It is all about the money.