If that is your only consern. The top is vinyl, so I doubt the wash would ever penitrate the top. But the chemicals could damage it. I think that the checmical would be a long term proble for both the top, and the paint.

Zaino is fantastic. I only have to wash my car once a week for it to look new. I can even take it two weeks.

A quick detail spray can help between washing. It take about 15min to do the whole car. If you did this say twice a week you might not have to wash for some time.

Since you live in Indianapolis, and I assume that it snows there. where do you store the car or do you still drive it?

 

I'll have it stored this winter, luckily I was able to come across a truck. It really doesn't snow that much, maybe one day with 5+ inches, other than that, its a dusting.