i cant remember now 
sorry!
Wheel Nut:
Karlovy Vary - Bayreuth E40
The sign i saw was where wheel nut said. Mind you, its not to say that me and mat saw the same sign, im sure theres more than one! 
E50 Prague to Brno not far from Brno race track on that bloody annoying section concrete road.
mattoni?
These Mattoni adverts are all over CZ and SK.
As you’re saying it’s road #2 and it’s motorway (dual carriageway) I’d guess it’s D2 between Brno (CZ) and Bratislava (SK).
Looking at the concrete character of the road (I bet you had a fair bit of shock abs and suspension testing), it “must” be just beyond Brno. In fact all the D1 between Prague and Brno is horrible