I wouldn't even mess with anything in a bottle. Start with wet sanding and save yourself some headaches. I was scared to try it but wish I would have done it 5 years ago rather than trying "miracle" products.
Start with 500 or 600 grit... wet sand it up to 1500 or 2000 grit. Then use a rubbing compound, a polishing compound and finally a wax. It will look like new when you are done. It took me about 30 hours this year to get mine done. I would have spent that same amount of time with rubbing compound but it wouldn't have lasted for even an entire season.
Former owner of a 1987 Supra Saltare. Current owner of a Malibu 23LSV.