Ian I will question that on 'date, prior usage etc. My example of the .de (German) domain was just to show Audi are Unlikely to be trying to 'Close Down' (or buying) any use of the simple reference term. RS1. I certainly wouldn't advise anticipating any sale to Audi. (which the original poster may or may not have alluded to) But I wouldn't be scared of leaving it on Sedo either.
My estimations were just a reflection of the memorability and association to 'Rally-Sport' which has history.
Too many people have 'Preconceptions' about domains (and occasionally TradeMarks) - which aren't really realistic, I'm not a supporter of 'Exaggeration' from any angle.
PS.I also notice RS1.COM is up for (advertised) sale at US$30,000 (price not disclosed on the homesite)