The sunroof is a huge weight increase because Tesla reinforced the entire B pillar with a stamped steel doubler and added lots of structure in the bodyshell to recover / exceed the closed car strength...it works out to ~150lb! and much of it is at the top of the vehicle to really sabotage CG height.
Really impressive since its basically a 75 kWh car. Once they move all cars to the new pack architecture and maybe reintroduce a real 60, the weight should go down a lot. Maybe even close to 4000, for the lightest version.
I fill my air suspension system with a helium recharge to lighten the car. Makes up for the added weight of sunroof. We drove onto scales with a fully load car passengers and luggage... and nearly hit 6000 lbs. My wife took it personally and began a new diet.
Even a "light" model S.. 4500 lbs. Honda Accord 3375 lbs, the heaviest 2016 I could find on the list.
You still win in any collision! (Don't worry about being too lite, and you can always add weight.. few sandbags in the frunk would be awesome.)
Obviously this is only light relative to other Model S variants. These are definitely not light cars
Also, the helium filled air suspension would be a net loser...reducing load on the tire and thus grip, but not reducing mass and inertia (and thereby the need for grip) but a similar amount... I know you weren't serious, but someone else will likely read it...they may be 12...and pretty soon the interweb is slightly worse.