I have the Black Leather Eddie Bauer High Back booster/carseat. I have taken 3 measures to minimize denting of the leather and to protect the NSX seat. I put a towel on the seat first, and then one of those thick rubber mats. The towel is my barrier between the rubber and the leather to insure the two don't start sticking to each other (I don't know if it would be a problem, but I'm not taking chances. Then on all of the plastic edges that are like thin knife blades where the carseat would push against the rubber mat, I taped 3/8 inch thick closed cell foam. This really insures that the contact pressure points are wide rounded surfaces instead of 1/16 inch wide "knife blades". I leave the carseat in for months, and on the few occasions (like NSXPO 2003) when I remove the seat, there is little to no evidence of the fact a carseat has been there for the last 6+ months.
But I do find that the angle of the seat belt holding the carseat in is not as secure as my other vehicles. So I used the belt that is for a tether (which the NSX is not equipped for) and modified it so I can cinch it around the back of the NSX seat to securely hold the carseat to the back of the NSX seat.
For legal reasons, I am not advocating that anybody make modifications to their carseats or install them in anyway not described by the manufacturer. I know what I have done, and I am very comfortable with the security I am providing my son. But I am not a child seat designer and therefore not qualified to provide any advice on how to install and use carseats. I recommend that after you install one, drive your car with the seat and no child to your local police or fire department. They will inspect your installation and let you know if they feel the carseat is adequately secured for safety purposes.
