(Page 37)
"All vehicles shall have all non-laminated safety glass windows with safety film on both sides, or
replace the windows with polycarbonate material".
While more than one section of the rule book is used to determine class legality, this is a common sense safety requirement. If the old vehicle had original
non-safety glass, the rule above seems to allow a Lexan replacement. But even if it originally had safety glass and the Lexan was set in the
stock frame, at a
stock depth, and with all
stock trim in place; I can't see why it wouldn't be allowed. In fact if it was a flat Lexan plate that did not replicate the stock contour you probably are at an aero
disadvantage! YMMV with the rule makers though . . .