I think you should have the carpet stretched first. It is important to get the carpet stretched so the backing does not seperate where the wrinkles are in the carpet. When you do have your carpet stretched make sure they are using a power stretcher. Pulling the carpet from one wall to the other with poles. After the carpet is stretched , if it is done right the carpet will not wrinkle after getting your carpet cleaned. Where the wrinkles were the carpet will have dirty and worn areas where the bumps were from people dragging their feet over the bumps. Then the carpet cleaner will try to make it look even again, this is why you should get the carpets stretched first. A lot of times there is a bunch of loose carpet fibers all over the carpet after the carpet layers are done and the carpet cleaner can make sure to pick up all of the loose fibers with their vacuum cleaner. The carpet cleaning should always be the last thing done to make sure the carpets look, smell and feel great, ready to get back to living in your home. When you are ready to have your carpets cleaned give us a call 801-756-2275 the Jeff and Judy team, a husband and wife team that care about your home and carpet.