Nice work! The steering mechanics felt great, and the shooting vibe reminded me of Death Rally.
You might be interested in a driving/shooting game I made for Brackeys game jam a few months ago: "Nuke N Rally"
Your AI opponents are very well done, I haven't dipped into the navigationagent2d class but after seeing this I think I will!
If I needed to come up with a suggestion, it would be for more tracks, multiplayer, or a leaderboard.
Good entry, great use of the theme!