The sales tax credit in Colorado means you only pay sales tax on the difference between the purchase price on the new car and your trade value. So if you bought this one for 65k and got 41k for yours you would only be paying state and local sales tax on 24k versus the whole 65k if there was no trade.
I don’t get the fear of a roll bar. It’s both a safety bonus and stiffens the chassis. But I always look ahead to cover the what if’s. I look at a cage as a safety item not as the car was beat. I like cages in daily driven cars because of all the idiots on the road trying to crash into me.
I have a fear of tunes, not roll bars. The concern is was there a tune to go with the bar and how hard was the car run. 1500 miles is not much and you can tell a lot looking the tires, brakes, paint, and quality of the mods. The key for me is that the dealer is willing to confirm they would not disallow any warranty claims on the engine today (no tune detected, which is basically comparing the key cycles to mileage) and that the compression is good in all cylinders. If so, then the bar might be a plus and at the right price then maybe a good deal can be made.
I'd do both on any used gt350, with or without a cage.
I wouldn’t fear the roll bar either. 90% of the ppl with roll bars do them for looks not function. Or plan on maybe taking to the track down the road but never do. 1500 miles is brand new. As long as you think it went thru a half way decent break in period I wouldn’t worry. When I was looking for a 350 I came real real close to buying a grabber blue 2017 that had a roll cage and front tow hook installed. It was “used” and had 64 miles on it. Highly doubt it saw the track lol