Yes, the battery trays are bolted only to the chassis. I didn't want ANYTHING on the plastic dirt guards, especially something as volitaile as Lipos. Don't need to be dragging my Lipos over dirt and rocks if the dirtguard breaks! :026:
Anyway, I used some nylon bar stock as a spacer because it is light, easy to work with, and self threads easily. I think I got it from McMaster Carr. It's about 10mm thick and about 20mm wide IIRC. 10mm is the perfect height to clear the dirtguard "nibs" (the little protrusions that the screws go into). Below is a pic of what I mean - the screw placement in the final design is a little different than this, but you get the idea:
As far as canopy clearance, I'm good. The shallowest part of the body is right at the edge of the sides, and the batteries don't go over that far. I still have about 3/4" or more of clearance at the worst spot. However, I did raise the body mounts about 6mm to gain a little wire clearance, so make that about 13mm without the raised body.