I use a silicone free dressing for vinyl from McGuire. Its in the tan
bottle, can't remember the name but it does a good job. Mind you you have to
do it more often as it has no silicone and it's also not as shiny than the
armorshit but it won't turn your tires brown like silicone does...Its part
of their pro line of products.

2 cents

Serge