I'm looking for the next step in agressiveness after trying Menz IP? I've been using a DP orange pad. Just looking for the next level to clean up my older truck. I'll be using a PC. The IP didn't clean up all the swirling / light scratching.
IP is edging towards the upper limits of whats achievable with a PC. However, Optimum Hyper Compound will do the trick, if you follow up with a good finishing polish.
#83 is more aggressive than IP and is still PC-friendly.
As suggested above, you can try IP again but alter your technique. Also, with some marring multiple passes are required to remove them, regardless of polish used.
You might look into the Hi-Temp line at TOL or consider 1Z's Ultra/Extra Polish.
But IMO the best way to up the aggressiveness of the PC is to use it with 4" pads. They make such a difference that you actually have to be a little careful.