After discussing this with friends, here's some of the suggestions:
1) After production of your new Roadster, Tesla should offer an opportunity to drive it on an approved straightaway at 200+mph--with appropriate safety gear and a Tesla instructor pilot--then when someone asks how fast you've driven it, you can truthfully say a third of the speed of sound. It may just prevent a horrible accident later when someone can no longer stand not knowing how it feels.
2) Limit top speed to something reasonable. Time-limit changes; require a long PIN or temporary code from Tesla to activate higher increments. Helps maintain Tesla's high safety ratings and probably lower insurance costs.
3) Offer a drag chute option for those wanting to race on an NHRA drag strip. A roll bar is also currently required. Maybe Tesla can certify the equivalent in the standard configuration.
4) Offer a 2-seat option that's cheaper than the 4-seat standard; more storage space is better. I had a too-tiny, fold-down rear seat in my '57 Karmann Ghia. It once held 2 of my fraternity brothers; I think one pulled a muscle getting out.
5) With no side mirrors, play up the safety features for changing lanes. Make it cool and reliable. My wife's Outback does a great job of blind-spot warning. My P85DL's acoustic sensors do not; one can too easily get scary close--for both drivers.
6) Have performance displays with G-forces (longitudinal and lateral), time vs distance vs speed, power/torque used, etc. The original Roadster's performance display was "under-powered."
7) Have at least dual screens like the Model S/X. There may be more displays to show what the side mirrors would have.
8) Do not glue and screw on front license plate holders, as done currently for Model S/X, to accommodate owners who live in a state that does not require a front tag--like Florida. A friend who took delivery of his P100D in Florida a few weeks ago begged Tesla not to put it on, but they refused. It's still a sore point for him. Angry drivers don't improve sales, unless they are in a Ferrari, Lambo, Jag, Porche, Bugatti, BMW, Audi, NSX, Vette, Viper (the car--not the F-16), GTR or Demon to name a few.
Over to you for additional ideas.