The three way comparison of Snugtop tonneau's done in conjunction with SEMA can be read about here:
https://web.archive.org/web/20061003133109/http://www.sema.org/main/semaorghome.aspx?ID=55785One key point to note is that
the three pickup trucks were only allowed to circle the racetrack at 45 mph
because they did not have fitted internal rollcages,
like the racetrack's liability insurance required.
That is a shame because a test at 75 mph would have more clearly shown the difference in aerodynamics
More from SEMA on tonneau aero on Dodge Rams here from some ASME prize winning engineering students at Western New England College:
https://web.archive.org/web/20050313154211/http://www.sema.org/Main/SemaOrgHome.aspx?ID=52546
