A “permanent” knob to replace the ignition key fob.
6 variants available.
Zip file containing 7 stl files and 2 pdfs (how-to).
Designed for Smart Roadster 452.
Might also work on Fortwo 450 & 451 (not sure though!).
Recommended printer: SLA or DLP (resin).
Supports required.
Print-tested on SLA with supports.
Note:
You’ll still need the original key fob to unlock/lock/start the car.
You might want to carry a 2nd regular key (with fob and blade) or a spare fob battery, in case of key fob malfunction (e.g. if the fob battery is empty), to enter the car.