Above: Air dam, stock (left), ecomodded (right). It's my first classic lawn edging air dam! It scrapes now and again, which tells me it's working.
There's about 3.5 inches of clearance (and it scrapes regularly).
Above: went from stock alloy wheels to steelies with winter tires which are taller and fill up the wheel well more. I attached coroplast discs by zip tying coroplast bundles to the wheel rim to use as attachment points for the screws through the disc.
Above: passenger side mirror delete. I'll replace this with a much smaller exterior convex mirror (because I often back into tight parking spaces) and a larger interior one also.
Mounted a convex mirror on the trailing edge of the driver's outside mirror (for highway use).
Added hard "corners" to the rear bumper in the form of vertical spoilers to promote clean flow separation, as on many newer, aero-focused cars (e.g. Volt, Prius, Mitsu Mirage).
Copied the Civic hybrid deck lid spoiler, left. My cardboard test version is just a little bit taller than the hybrid one. I'll reproduce it in coroplast for the winter.
Also copied from the hybrid: rear wheel spats.
Above: showing the stock grille and front plate bracket (left), grille blocks & plate relocation (right). The lower block has a quick-removable section in case things get warm.