Your robot is not rigid. It will lean slightly to one side no matter what your vehicle looks like. Getting a perfectly straight launch is near impossible.

It looks like Shocks might be causing problems, too.

More specifically, multiple parts attached to a Shock node. There's too much flex with just a Wheel on a Shock, so attaching Braces and solid pieces can help, but I regularly run into a broken Go button with complex designs like that.

For some reason, Piston just took over "H" from Shock. That's odd.