Charlie Johnson's excellent suggestion: carry a small bottle of soapy water- give the traveler car several squirts and wiggles when mounting up to go out. Splash it some and all the dirt is flushed & gone.
Repeat as necessary....like every time you go sailing.
Round Torlon balls/hard plastic body/anodized aluminum track...everything wants to be CLEAN!


Dacarls:
A-class USA 196, USA 21, H18, H16
"Nothing that's any good works by itself. You got to make the damn thing work"- Thomas Edison