alongside this one:Maximum of two traction magnets. Open choice on strength and material but must retain standard chassis position and size.
The two together suggest to me that racers may only put traction magnets into the holes that exist for the original magnets in the chassis. You can use smaller mags and fill out the space (not with glue), but that space remains the same.No part of the chassis may be cut, sanded, drilled, glued or otherwise interfered with unless it is for the purpose of fitting a body to the chassis or to access enclosed traction magnets. All general wear must be by natural means only.