I would take off the OEM fabric, screw on plywood backing and then put fabric back for OEM look. Aluminum would work too if you wanna go that route. I'll take a look how it is attached, but normally seat covers are put on as a sock and kept in place with hog rings, so at worse you'd need to take the upholstery off the seat back and then put it back on.
Originally Posted by SS1
youtube removing seat covers to get an idea how hog rings used.
Alternatively you could just put black painted aluminum plate on top and not worry about upholstery.
Do they have mandatory baby seat anchor points on EU spec cars?
View my fuel log 2015 Mirage DE 1.2 manual: 46.4 mpg (US) ... 19.7 km/L ... 5.1 L/100 km ... 55.7 mpg (Imp)