problems with my new carpet

I got my new carpet from supercoupe performance,I have the adhesive that your supposed to use,but this carpet is not all that plyable,when there is a corner it kind of folds instead of forming right in there like the old one did,now I know the old one has an advantage due to the fact its been there for over 20 years. So are there any tricks to make this install go better,I have the carpet sitting in there now see if i can get it to form and I left it in the garage where the car gets really hot inside,any other suggestions would be appreciated.

it formed a little bit by me letting it set in there,however i did notice on the old one from the factory that there seems to be a solid piece of fiberglass molding under the carpet in the rear to formed just like the area is shaped,and they glued the carpet to that,that is how it fits so perfect,not sure if i need to remove that and put it on the old carpet or what.

I would call Bill at SCP. He is very nice and will help you with your questions.

just in case anyone else decides to replace there carpet and order from bill at supercoupe performance,be sure to invest in a heat gun,that makes it soooo much easier.