TC02C exposed spur and pinion

[Dadio]

Hi ,I've been building up a TC02C and it has an exposed spur and pinion gear ,how vulnerable are they to dirt ingress ,specifically sand ? I'm planning on taking it to track days at an outdoor astro track and i think that should be pretty safe ...but the only place to practice/bash locally to me is sandy and I'm just wondering how abrasive it will be .I made the mistake when cutting out the body of following the suggested cut lines and that leaves quite an opening around the gears but I could have cut it leaving it far more covered so I'm tempted to get another body shell and cutting it differently to use off track ,but am I worrying about nothing ?