To those comparing used to new prices now, you haven't looked lately. It is very seldom that you find a sub 30k mile vehicle that is a year old being much less than 5-10% off of the new one's price. Back in the day, that difference would've netted maybe a 20-30% depreciation. Anymore, it's not so much new versus used, it's simply people spending more than they can afford.
The OP's scenario is slightly different, but fits. Sure, you're doing fine and making all your payments, but one thing goes wrong and you're screwed. And for me, a truck is about the most ridiculous thing you can buy brand new unless you're regularly putting it to use as a truck.
All that aside, used vehicles aren't the dilapidated pieces of shit some are referring to. A 5 year old car with 100k miles is likely still good for another 100k miles. Hell, I've heard of people with brand new cars that have been in the shop more than my $6000 Equinox. All cars are prone to have an issue here or there, and new doesn't remove you from that possibility. I personally feel that a 2-3 year old car with 30-50k miles should be in perfect shape for several years of use.
Meh, I'll simply suffice it to say that a 30k car in my garage doesn't make me feel that much better than my 2007. Actually, the payment in most cases negates the positive feeling I get from having a new car. Now, having a car without a payment in the garage is a slight net positive. If the transmission blows, I don't give a shit because I can just get it fixed and keep driving it payment free.
I've just seen too many people with poor debt situations and someone loses a job and you're looking for ways to save money. Easiest way? Sell the thing that has the most value that can be replaced with something of lesser value.
That is not to say that you shouldn't buy a new car, but getting a new car every 3-5 years is overkill, IMO, if you maintain your vehicle properly.