Although the vinyl mats are quite popular, I refuse to sell them as they look so cheap in my personal opinion. The vinyl mats are basically a printed shower curtain that comes to you in folded up shrink wrap. Getting the wrinkles out will take a considerable amount of time if allowed to sit folded up for an extended period of time.
For the 68 to 69 Plymouth B-Body applications, you will be either purchasing an ACC or a REM product. REM is the only manufacturer that offers both trunk pan styles as the spacing differs and you need to verify the trunk supports prior to ordering the mat. Measuring from the center of the trunk latch to the center of the right hand trunk support, it can be either 13.25 or 14.75 inches. This makes a big difference in getting a mat that fits properly. You may still have to do some minor trimming for the best fit.
Although ACC list the mats as being "vinyl", they are actually the heavier rubber mats as the factory style. REM offers both the cheaper "vinyl" and the rubber mats. The ACC mats are slick on the back side, where the REM rubber mats have a texture like the factory mats.
Depending upon how the car is stored, condensation is a problem with all of the mats. If the car is in a humid environment, you may want to check for moisture buildup under the mats. This is one reason that the trunks rusted out so bad on some of these cars.
I received on Friday a product bulletin from REM that effective March 1st, the trunk mats would see a 7% increase in our wholesale price. So prices will be increasing in the weeks to come for us vendors offering the mats as we carry both the ACC and REM mats.
Hope that this helps.