I have a question about a trade in sales tax credit. I live in WA and if I trade in a car that is worth 35k I get 3.1k of sales tax credit. I may be wrong but I don't think that I would get this credit in cash but it's rather applied to the next car. So what happens if my next car is cheaper than 35k or it's leased (so the sales tax owed for the new car is lower than 3.1k)? Is there a way not to lose the difference?