We're getting a local to make some water proof bed ends for us. We have opted for vinyl, with zippered corners and on sail track. They will be used for wet weather protection, and when we want to run the heater or airconditioner. My question is that the sail track will be put along the 'lipped' areas under the lid which leave a gap of about 15-20cm along the side to the front (where there is no lip, and then again for the short sections where the lid locks are.... do you think these gaps will cause any issues? I image that there are greater gaps with the press stud method but just wanted some feedback on what you all think.