Getting ready to install the 3/4 inch 4x6 mats in my stock trailer. One side of the mats has a groove cut in them about every inch or so running the 6 foot direction. The grooves are about a quarter inch wide and about 3/16 inch deep. The other side has a little raised oval shaped dimples on it kind of in a diamond plate pattern. Which side should I put up? Looks like the grooved side would provide more traction, but the grooves would be running crossways of the trailer and seems to me would make it harder to wash out the trailer. Also, my trailer floor is 5' - 11 inches wide. Should I trim the mats to fit that size or just force them in and leave a slight curve on the sides. Someone told me that would make kind of like a curb on each side to make it easier washing the trailer out? Thanks! gwece