I removed my enclosures at the start of this year and brought them home. Set up a sheet of plywwod on sawhorses, padded it with towels then used Plus 210 scratch remover and polish to remove any fogged areas. Finished with a Clear Vinyl polish (think it was by 3M) and they came out almost like new. Lots of elbow grease but worth it for the great view.
I reread you post and wasn't sure what king of vinyl you wanted to clean. Good old furniture polish- even the dollar store kind does and awesome job on the clear vinyl and also puts a protective coating on it.