You most probably have gelcoat. The blotchy spots are hard to diagnose without better description. If they are dull, then a cleaning polish may help. I suggest Meguir's cleaning polish for gelcoat. Try a small area first to see if it will help.
The other possibility is that the previous owner damaged the gelcoatby being too agressive with a buffer or the like. If that is the case I perssonally know of one solution and it is expensive. The coach can be painted, but the process is expensive as the coach must be sanded and preped to make the paint adhere properly.
2004 Itasca Sunrise 36', Workhorse
2003 Suzuki XL7