a cautionary tale
ok, I wasn't going to comment, but since over 1,000 people have viewed this, some general advice might not hurt.
Not a criticism at all of the poster, he asked for advice, and got it, and did what he found worked....perhaps with some risks!
Plexi is funny stuff, and most haven't much experience with it.
the face is much tougher than the edge, often treated to be UV or scratch-resistant after processing, ( more common with Lexan). As others have said, use the manufacturer's recommendations, if you can get them.
whenever you get a scratch or paint or dirt on it, always start with the most simple, and benign solution possible.
warm water is good, soap and water likely better as it carries away impurities that could stick to the surface.
if the paint or sap or whatever is really stuck on there, something like peanut butter, ( hey, gets dried paint off my hands!) or mild solvents like mineral spirits ( plain paint thinner) or the 'alcohol's recommended, though most of those evaporate long before any effect on the stuff stuck to the plexi.
Caution: orange ( limonene) solvents can be harsher than the strongest petroleum based solvent!)
certainly, high level hydrocarbons like acetone, toluene, both components of lacquer thinner, are 'high-risk'.
Acetone ( as methyl methacrylate) is a component of most plexi GLUES, which dissolve the acrylic, thus welding parts together!
..... you may get away with them on new, soft, warm, non-stressed acrylic sheet, but as the material ages, UV reduces the plasticizers, or they are stressed by age, bending, or hot vacuum-forming ( gee, a canopy !) they are much more subject to damage such as the tiny stress cracks or risers that you hear about.
I've washed large sheets of plexi with lacquer thinner to remove paint, successfully, but eventually fresh thinner on old weathered plexi with numerous cuts and chips in it would craze and turn almost opaque, or crack into a thousand pieces.
I just don't want to hear of anything bad happening to your $1000 canopy.