The real problem is, employees during work hours think more of unloading "product" than other people's purchases,without placing blame on anyone in particular.
It's quite a chain; this could have happened during the loading process,OR before for that matter... driving over a fairly high ramp,or at too high a speed that the front end "scraped".
During unloading is also a possibility,OR after it was unloaded and a car jocked scraped the underneath when he got it too close to a parking lot raised concrete end block... he probably parked many other cars in this same spot and never scraped, but the lower front end of a mustang was just that much lower and DID scrape... doubt he will run up to his manager and tell him he scraped a new car,that's the perspective of probability!
However this happened does NOT matter to you,the fact is that it DID happen to the car you are about to buy as BRAND NEW,and as much as offers of "repairs" are tangible,I much rather hear "replace with new part" from dealer...so yes, your stance is valid and expected.
I bought a lawn tractor (22 HP top of the line John Deere) for just over $4,500 this summer for my cottage... I was notified my tractor had arrived and I can go pick it up the following day, AFTER it cleared inspection and spec adjustments.
When I went to pick it up,I inspected it myself with the salesman,and lo and behold a major dent in the tub body; some 4" x 6" next to the drive selection lever,and this was NOT underneath,but right in easy view was staring right at me!
Essentially,I was offered a $200 deduction,which I turned down,and demanded the tub be replaced with new... 2 months later a service tech called me and said he'll be dropping by,took the dented tub off and replaced with new.
The point I mention this is: it's a $4,500 lawn tractor, not a $40,000 NEW car...problem solved to my satisfaction,even if they offered me a $1,000 deduction,I still would have turned the offer down, but that's just me