Hi,i make carbon fibre laminates and have the following issues at some parts which get direct sunlight in the hot interior of a car

In the hot sun dark coloured interior parts can get above 60C. The average pain threshold for temperature for most humans is around 54C yet even here in the "sunny" UK it is common on a hot day to find it initially painful to sit on or touch black leather interior trims or metal gearknobs

You will find most effective post cures will go upto or very close to the target heat distortion temperature. So if you want to achieve a 140C Tg on your resin (if it is suitable of course) then your post cure will likely hit at least 120C.

Your resin manufacturer should be able to give you a postcure schedule for the resin system.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant