Built-in online co-op can desync the two RC cars (wrong positions on each other's screen, puzzle states firing out of order). That makes progress impossible on a physics-heavy co-op game. Local split-screen never has this issue because both cars run on one machine. The workaround is treating the session like local split-screen even when you are remote.

1Decision Point (choose first)

Same room, two controllers
Use local split-screen
No extra steps, no desync risk.
Different locations
Use Steam Remote Play Together
Instead of the game's own online co-op. Only one PC simulates both cars. The remote player sends controller input and receives the video stream. Demo-era reports said desync showed up in standard online, not Remote Play Together.
Friend Pass still applies (only one purchase needed). Use Discord for voice. The game has no built-in voice chat.

2Remote Play Together (the online workaround)

Why this order: The game instance never leaves the host, so physics stay in lockstep. Streaming adds latency but avoids the netcode desync that broke puzzles online.

3If You Still Want to Try Built-in Online

Common Mistakes to Avoid