Adds a retarder/engine brake to the citybus, the controls are as follows:
Page Up - Retarder Up, increases retarder
Page Down - Retarder Down, decreases retarder
CTRL+Page Up - Sets retarder to max
CTRL+Page Down - Turns retarder off
You must add the part for the retarder to work! It's located under "Additional Modifications".
Me - Entire LUA code
BeamNG - The bus, LUA code I used for reference