Done the Monte Carlo trip last year, via Nurburgring, then Stelvio Pass. Awesome, awesome road-trip, but damn, we did clock up some miles! Worth it though, as blatting through the Alpine tunnels, driving to the top & then down the other side of Stelvio, doing a 'lap' of the Monte Carlo grand prix circuit, and then cruising along the French Riviera to Port Grimaud/St Tropez was absolutely top darts.
Best. Holiday. Ever.
A few pic's (literally!) in this thread:
https://www.rtoc.org/boards/showthread.php?t=38