I'd probably sell one of my cars first.
Each time I make a car payment on my cadillac sts, i think, I could have bought a Glock with that. Not that I'd need or want 60 glocks over 5 years, (one is fine with me) but I try to think of every purchase in relation to gun and shooting related component purchases, and I get depressed.
I can't possibly see cashing in all the guns and buying a car, I consider the number of guns i have to be considerable, but I realize you rarely get what you paid for them, or what you put into them. I would estimate I'd get anywhere from 15-20thousand for them all, and what would that buy me in terms of a car? Nothing I want.
I'd prefer to wait for the super low financing loans that were around a couple of years ago, anywhere from 0% to 3.9% sounds a lot better to me than cashing in all my toys.
If I cashed them all in, I'd have a car which I could drive to the gun range, and nothing to shoot when I got there.