I transport my road bike with the front wheel removed and a cheap tarp (faux canvas, Home Depot, ~$10) under it. I leave the cargo floor flat and push the front passenger seat forward a little. The rear wheel is toward the front and the fork to the back. There is room for the bicycle pump and my gear bag in the back also.
I saw where someone removed the cargo area floor and was able to put his "wheel-on" road bike in his car in an oblique fashion with the rear wheel down in the well and the front wheel atop the folded-down rear seats and against the front seats. (He also got road grime, black tire rubber, and dirty chain ring oil all over his carpet and seat backs!)
I plan to sew four "cord" fasteners to the tarp perimeter. Two loops will engage the "privacy panel" hooks in the rear sidewalls and two plastic "S hook"s will attach to two of the headrest supports in the front to put "sides" & a "front wall" on my tarp. I roll up the tarp dirty-side-in for cargo pit storage and run it (alone) through the wash every two months or so.
Happy driving AND cycling!