Re: Plastic tiles on kitchen walls
Easiest approach is 1/4" sheet rock, skim coat it and apply what you like. I would find my studs first, mark them and start rocking it. You could also glue the rock with liquid nails for a firm backing but you' still need to use screws as normal. I normally, with plastic backing, pre-drill/countersink with one bit and set screws with another. This prevents having the plastic blister beneath your screw and raise the level of your surface which would make it uneven.
Having said all that...In many cases, that old tile adhesive for plastic tiles is water soluble. About half the time it melts under water. But, if you have wall forgiveness for space, why bother?
If I only knew what I was doing!