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

Yep, much hotter. Post cure at at least 60.

What type of post cure profile do you suggest?elevated or direct?

That will depend on your resin system. You'll need to consult your systems TDS. 

I use megapoxy 132,the tds is not availiable,the shop where i bought it said it can withstand temperature over 130degrees if post cured,but they not give me extra information

Its almost always a "stepped" post-cure cycle ..     2 hours at 40, 2 Hours at 60, 2 hours at 80 ... etc.     Doing something like that will never damage the parts, and will almost certainly improve them.

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I backe the parts at an oven with elevated temperature,2hours at 40,2 hours at 60 and 2 hours at 75,after the cycle,the parts ofcourse get warm and epoxy get soft,you can hit them with your nail,is it ok or did something wrong?

You need to let it cool down again yes. 

I let the laminated parts to cool down,they get again rock hard,the clearance of epoxy is at higher levels,the abs plastic core get hard again!

Clear coat won't prevent print through if it does reoccur though. If the post-cure doesn't help, you may have to consider switching to a higher Tg resin system.