Be careful though.........Wesleys can actually burn the vinyl if not used correctly............
Simple Green goes easy on the vinyl compounds, and is used with a small scrub-brush at full strength.....scrub small areas at a time, wiping it off with paper towels before the area dries. After this, scrub lightly again with a diluted solution, drying thoroughly. Wipe it all with fresh water and a soft cloth when it's done.
When dry, treat all the vinyl with STP Son-of-a-Gun (it actually works a bit better than Armor All or similar treatments........Lay it on liberally, letting the old vinyl drink it in. Let it set "wet", and reapply to "dry" looking areas.
Next day or after a few hours, wipe it down with a soft cloth and VOILA' !!
No joke........we've used this method professionally for decades. Your vinyl will look better than new in some cases.
Good luck !