Tried printing the original STLs but there was too little room for my RX, as my CAD skills isnt that great I decided to make entirely new parts, the frame and cockpit. I also redesigned the Wheels to be able to fit 6x3x2.5mm ball bearings to make them spin more freely.

https://youtu.be/oOOwaBE1-oQ

Parts you need:

2pcs LEGO tracks, LEGO part number 43903 3pcs 4.3g servos 1pcs FlySky FS-R6B receiver, case removed 1pcs Suitable transmitter (I use the Turnigy 9X) 2pcs 1S LIPO batteries in parallell 8pcs 6x3x2.5mm bearing 4pcs M3x15mm screw 3pcs M3x12mm screw 2pcs M3x30mm screw 2pcs M3 nut

The two driving servos need to be modified for continous spin, just cut the pin in the servo protruding to the pot, connect it to the RX and adjust the pot using a small screwdriver to the point where the motor stops.