Vehicle Alignment When Reversing Direction

[Orion66]

When my mousetrap vehicle goes forward, it follows a relatively straight path. But when it reverses direction, its return path is noticeably more curved/misaligned. I've checked, and I don't see any slipping between the wheels and the ground. If my intuition is correct, a vehicle going forwards then back -- regardless of how the wheels are aligned -- should at least pass through the initial starting point on the way back. Yet this is not the case with my vehicle.

Any ideas as to why this might be happening? Thanks!

[terence.tan]

When my mousetrap vehicle goes forward, it follows a relatively straight path. But when it reverses direction, its return path is noticeably more curved/misaligned. I've checked, and I don't see any slipping between the wheels and the ground. If my intuition is correct, a vehicle going forwards then back -- regardless of how the wheels are aligned -- should at least pass through the initial starting point on the way back. Yet this is not the case with my vehicle.

Any ideas as to why this might be happening? Thanks!

the vehicle dose not have to drive straight when going forward, it just needs to go back to the center line when going backwards
After a couple of test you will find the sweet spot.