people put the zed on a diet, but even then she's still heavy,
the chassis is hugely heavy; i think they hired brunel to make it out of pig iron all those lovely comfort parts you like; for example the seats, air con, radio, glass, carpet, centre console, and safety features all weigh alot,
the boot lid is hugely heavy; also the LSD, gearing and engine aren't light either.
if they were to do an no expense spared job on the zed, the chassis would be aluminium, the body would be carbon fibre, the engine would be a smaller V6 but supercharged or turbo'd from the factory, the seats would have no electronic gubbins but be functional carbon pieces. the dash would be minimal, the glass would be replaced (if it was for a track car) with plastic.
and no fat people would be allowed to drive it,
oh and it would then probably cost over 100k