Not willing to bully an innocent hairdresser I held back but he seemed up for it so I persisted in this scientic experiment.
On the exit I got onto the power way sooner and pretty much caught up with him (he'd moved to the left hand lane) and there was very little in it until I managed to squeeze a few more revs than him and gained a car length.
Power to weight ratio is 243 bhp/tonne for RS4 (assuming 414 bhp) and 237 bhp/tonne for Cayman S which considering Porsche bhp is usually as stated or more wasn't a bad show I suppose, a big grey Estate car keeping a little Porker honest must look great!
I had Radio 4 on but he had grey hair so we were on a level playing field
Maybe next time we'll get out of 1st gear