3 passes at speed 6 sounds kinda too fast to me. to me, it sounds like the SSR 2.5 is being broken down too quickly and not having enough time to polish the paint.
i like to use SSR 2.5 this way: with the PC off, spread the polish out on a 2 x 2 area. turn the PC on and further spread the polish out in the area i am working on at a low speed. at a speed of 4, i go over the area with very slow passes a few time. i then bump the speed up to 5, and continue to make slow passes until the polish pretty much disappears. this usually removes most swirls and leaves the paint ready for a LSP. sometimes i'll get light hazing, so i'll follow up with SSR 1 and a polishing pad.
so maybe try slowing the PC down a couple speeds, make slow passes, and allow the polish time to work.
btw, got any pictures of how the car looks now?
good luck.
