Hi Carl,
Hope you and the gang are keeping well mate.
The Sealey is a rotary and yes, there is a big knack to it. For car polishing you are looking for rotary speeds in the region 600/900 rpm - 2000ish rpm. The lowest speed on the Sealey is 1400 rpm, so refining any polishing may be difficult, depending on the severity of swirling you are trying to remove. This is particularly true for your A4's clearcoat.
I'd buy a Dual Action if I was you. A bit more expensive but a lot safer, but still very very capable. Having done the paint correction on your two cars last summer myself, you should get through the wsirls no bother with a DA. The A4 saloon in particular has most panels resprayed (except the roof IIRC) and has a very soft clearcoat. That I do remember!
Polishing pads for both the A4 and S4. Menzerna 106FA polish will give get rid of minor swirls on both cars if worked slowly enough to a good degree of correction. Light pressure on the soft A4 and medium-firm pressure on the original-paint S4.
I think one of the Polished Bliss Guides give some more detailed analaysis on machining with a DA, as do some of the threads over on Detailing World.
Hope this is of some help.
JOHN
