I have had my 65 for almost 2 years but had never taken the back seat out. Well I did today and the seat looks good, upholstery looks great but found that under it was insulation like you would put in your attic. Is this common? I had driven the car for about an hour and the floor board was hot to the touch under the seat. The insulation is very old and if this is common then I will replace it, or if there is something else that is used please let me know. I was hoping to find my build sheet or something fun since I have heard stories about that happening, but no such luck ha.

 

Not factory, but no problem. Your exhaust runs right under the seat, a prior owner probably put in the insulation to keep the heat down. There are all kind of heat insulation materials out there (fatmat, etc.) that you can use, but if the old "cotton candy" insulation works why mess with it?