I see the Renault Ami much better for this use.

  - It's bigger (seats two tall people very comfortably. Or one plus your shopping.)  
  - It's half the price (12K€ for the Twizy vs 7K€ for the Ami)  
  - It has windows :P  
  - There's a "cargo" version (it substitutes the second seat for a cargo space).

https://www.youtube.com/watch?v=yb9-pbLk3Go