I saw a thread a while back but cant remember what product was best to use and also how to install

Go to a local plastics place and order mirrored acrylic. Glue it on with some 4200 or 5200 and maybe screws on the corners.

thats the correct material, we use it in my sign shop, but if you use screws, put trim around it and screw that, do NOT screw thru the material itself as it will crack at some point..Rob

I pulled the mirror of my '98 Hustler Slingshot last month, had to take it off to get to the sun pad. Mine had 1 1/2"x 3/4" furring strips glassed to the under hatch and screwed to the hatch. The acrylic mirror had a luan subflooring glued to the acrylic. The mirror had holes drilled into it, rubber grommets around the holes with a screw holding it to the furring strips. This came from that factory this way.

Mirror finsh stainless steel sheet metal is the best solution. It won't crack or warp. I've had both, and the stainless is still there 5 years later.