Megs 205 is just sooooo Good!
I've just ordered a big bottle of this and a little bottle of 105 for the bad bits! I'm new to machine polishing so have that nervous excitement thing going on! I've just got the Das6 pro from CYC and it's shockin how much noise it makes! 
this.
however, 105 can be deadly in untrained hands, if thats the case, then use the slightly softer, but just as good, ultimate compound
(btw, im just quoting directly from meguiars)