one nice thing with smaller cars to is that the tires will be wider in comparison to the vehicle adding to flotation, as opposed to thinner wheels of the larger scale acting as pizza cutters into the sand and sinking. as well as what he said them being single speed, so larger tires would be a...
main thing i can think of is cost of repairs, seems like every part is at least 5x as much as a 1/8 or 1/10 scale. that and size, but if you are running on a beach room shouldnt be an issue, invest in alot of cleaners though, and bearings, sand is hell on bearings and any drivetrain.
if they...
that does look like to be everything that i am aware of that are problem areas, though i would probably recommend buying an extra set or two of driveshafts, and one set of RPM A-Arms, and swap them out as they break. (RPM for a lack of a better term doesn't break). i would try to find a bearing...