In case you are interested in low weight you should start a list showing where weight reductions are feasible and what they will cost.
For the beginning:
Magnesium wheels
MMC or carbon- ceramic brake rotors.
Titanium whish bones
Titanium drive shafts.
Carbon and Kevlar fibres instead of glass fibres plus Epoxy - instead of Polyester resins
Exhaust piping and silencer in titanium instead of steel. (Also good for power output)
Smaller alternator and battery.
Carbon - Kevlar fibre seats.
Rear window in polycarbonate (Lexan), does not break when stones fly over the windscreen.( thathas happened already some times!)
I am sure there are still more.
Perhaps your Elise must not be spelled the “Fat Elise” anymore though a 650 kg will be very difficult and expensive to reach.
For the beginning:
Magnesium wheels
MMC or carbon- ceramic brake rotors.
Titanium whish bones
Titanium drive shafts.
Carbon and Kevlar fibres instead of glass fibres plus Epoxy - instead of Polyester resins
Exhaust piping and silencer in titanium instead of steel. (Also good for power output)
Smaller alternator and battery.
Carbon - Kevlar fibre seats.
Rear window in polycarbonate (Lexan), does not break when stones fly over the windscreen.( thathas happened already some times!)
I am sure there are still more.
Perhaps your Elise must not be spelled the “Fat Elise” anymore though a 650 kg will be very difficult and expensive to reach.