I bought the dual bucket dolly five years ago. Yes it was expensive but you get what you pay for. I use the product often keeping three vehicles clean and it works just as good now as day one. Real nice piece of gear to tote around your two buckets as you move around the vehicle.
Ed
I just use whatever good car soap I have when I wash my boat. I pull my boat out after each use, completely wash the boat, let it dry a bit and then put in inside the garage. I run a SeaRay 205 Sport.
I have five. One doesn't work either... it sprays in only one direction (on the pull) and now leaks all over the place when you try and use it. The other 4 are good so I guess 80% working isn't failure but still not where it should be with their cost.
My favorite is Wolfgang Deep Gloss Paint Sealant, but I like everything I've tried in the WG line. I use WG products most often when making vehicles shine.
Ed
Yes- I say rotary is best for gelcoats on boats and RVs that have a lot of oxidation. I use a Flex DA on my boat but is sits in the garage when not in the water so is very easy to maintain.
If you are new to professional detailing and are seriously considering this new job, I would make it a...
Finally, I always loved "Autogeek's What's in The Garage?" series.
[ame=http://www.youtube.com/watch?v=6EALqHhvUgA&list=PL2B48A5B20EA71FC2&index=9&feature=plpp_video]Season 1 - Episode 9 - Autogeek's What's In The Garage - YouTube[/video]
Mike has a lot of great videos and I used a lot of them when I was learning the art and techniques of properly detailing a vehicle.
[ame=http://www.youtube.com/watch?v=3xJH_MGgbLw&list=PL3D7FB26D1D6B6611&index=4&feature=plpp_video]How to remove shallow RIDS and how to machine apply both a paint...
And one more great beginner video
[ame=http://www.youtube.com/watch?v=NURjFvmDpEc&list=PL3D7FB26D1D6B6611&index=56&feature=plpp_video]Porter cable 7424 light swirl remover - YouTube[/video]