Both Probe and Civic were relieved of the rear seat and belts, as well as both exterior mirrors. The Probe got an interior convex mirror and the Civic got a small, custom exterior convex one to comply with Michigan law.
Civic's spare tire was gone long ago so I carry a Slime kit, tow strap, jumper cables, jack, tire iron, safety vest and other emergency and/or safety equipment.
I replaced the fiberboard rear cargo shelf (floor of the cargo area) with blue styrofoam sheets for weight savings, and am considering removing the passenger side wiper and rear wiper for another couple pounds + a tiny aero gain. In due time...
The car also has no badges. Which doesn't make any functional difference at all.
Of course cycling to work helps "delete" extra pounds from my belly, but Oreos keep it coming back.