i have a black vinyl top on my 69 charger
I use just standard car soap to wash/clean the top
when im done washing the car, i usually rub some chemical guys VRP dressing on it
Great shine and protection, only downfall is it seems to collect dust. After a week or so the car is ready to be washed, you start all over.
I dont know if there is something better than that, but VRP works great, just attracts dust
I just ordered some Chemical guys silk shine to try....according to them its not as "wet" when its applied....so hopefully wont attract dust