Obviously not a Civic, but I wanted to point out that there are roof-top and rear bumper carriers. The obvious problem with rooftop carriers is the increased frontal area. Perhaps not so obvious is that a rear-bumper mounted bike could possibly act as a perforated base plate and actually improve the aerodynamics. On a Civic possibly one of those stunt bikes standing off from the bumper a foot or so.
Also mounting and unmounting the bike is trivial with a lower rack.