We did. You can see if a car seat has been damaged. Our capsule is an ebay purchase and it has "done the rounds" amongst our friends too. All of our friends knew it was an ebay purchase, all were satisfied that it was undamaged.

IMO the recommendations on "don't buy second hand, it might be damaged" are there to protect nufties who can't be trusted. In the same way all baby shops have "car seat fitters" on standby. Because only a "professional carseat fitter" can be trusted to do it right? Yeah, so some guy who has READ the instructions is a "professional"? Hmmm.

I'd rather let my engineer DH fit the carseat....