I think you’re onto something with progression. The core mechanic was strong enough that I gave gameplay a 5, but once it clicks, there’s definitely room for the game to start asking more of you.
Something I’d love is for the progression to happen visually AND mechanically. Like the first stretch is normal highway, then you start getting construction zones, weird vehicle combinations, ramps, tunnels, different road surfaces, etc.
That could also solve one of my biggest criticisms, which was that the game plays like this ridiculous skating/trick game but visually still looks mostly like a normal road trip.