This is looking pretty neat so far!
One thing that would be good to address: when Automa vehicle is in a slam and it is the larger of two vehicles, will it always/sometimes/never ask for a re-roll?
The only potential gaming of the system I could see is many players directly staying behind the Automa vehicles, since the only direct threat is the vehicles front arcs, and the vehicles will always play it safe (ie never try to boost their own via slamming). No repairing option (save for a card's event action if you had put one in) will most likely mean others may try to bang up the AI first and slightly tilt races towards a quicker game end (unless you want to put in your rules elimination of the AI does not trigger final tile in 3+ player games).
Looking forward on its refinement!
One thing that would be good to address: when Automa vehicle is in a slam and it is the larger of two vehicles, will it always/sometimes/never ask for a re-roll?
The only potential gaming of the system I could see is many players directly staying behind the Automa vehicles, since the only direct threat is the vehicles front arcs, and the vehicles will always play it safe (ie never try to boost their own via slamming). No repairing option (save for a card's event action if you had put one in) will most likely mean others may try to bang up the AI first and slightly tilt races towards a quicker game end (unless you want to put in your rules elimination of the AI does not trigger final tile in 3+ player games).
Looking forward on its refinement!