@FlyRetroGamer thanks for the comment, I agree that damage could occur and to other units similarly sized in length, I recommend you check for any microcontrollers that could be in the way before making a modification. The proportions of the mk4 are loosely following the real life counterpart, if memory serves right there are lots of medium sized batteries found in the undercarriage. You may replace these with small ones as the power draw on the mk4 is minimal when not in use.

This is currently one of my favorite creations. Great job on making it! One issue I have with this coach is that at high speeds while climbing slopes it gets heavily damaged. I solved this issue by removing .25 meters from the rear bottoms of the carriage.

I really think you shoukd integrate a better easier-to-use system of controlling the cabs from the drive car

cars are useless, cant turn on any lights or unlock any of the doors without the master switch, which once pressed locks the master switch in the engine car. If the master switch in the engine car is pressed, the master switch in the cabs locks and none of the buttons work (lights ect)