If you wanna plastic coat foam why not just make it out of this stuff????

Just ordered an a4 sheet to test it out but its 3mm thick closed cell foam coated in pvc. Im gunna do a tester when it arrives as long as its easy enough to cut then its what im gonna make the next project out of. If it works out i may have to fibreglass the back but should save me having to use bondo over the whole outside. Will let you all know how i get on peace out :thumbsup
Foamalux Foam PVC Board Red 3mm A4 210 x 297 PVC Sheet A4 | eBay