Experimental idea: configure the bus before doing the route runs

I "found" some additional parts for Wentward such as a more powerfull engine, NOS and it came with rockets. Wouldn't that be fun to try out while doing the bus route. To try this idea out we'd need acess to the vehicle configuration before pressing "Start" button to drive the bus with the configuration chosen

 

Can't you spawn it & restart the route by pressing R or something? Should work

 

What do you mean? I selected the bus route, the bus and the scenary. It spawned but i haven't been able to mod it b4 setting off

 

He means to be able to edit the bus for the scenario.

 

And select it from the vehicle list with the engine?
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How do I acess the config where I saved a config with the 15L cummings engine becaus ethe filters don't seem to show that variant