my car is small and a convertible, so no trunk space. i had 20" folding bike (Dahon clone) in the back seat and i didn't like how big and bulky it was (sold it). taking this on the metro or bus is probably out of the question....once or twice maybe but during Wash DC rush hour everyday, forget it.
for daily commuting to the metro, i think something that would fit in a rolling case/cheap suitcase would be the solution right? 12 incher then?
You would be better off with a 16 inch dahon or downtube.If it is any relation to a z bike it will have a too short seatpost and too low gearing. 3 speed gearing will be derailluer and if it is a 12 inch gearing will be especially pitiful.By the way I owned a Z bike. I ended up selling it cheap to someone for their childs use.Get something you will like not something you will grow to despise.Do not buy just because the price is right that is false economy.
I bought a TST1403A (14" wheels, 3-speed) last December and wound up giving it to my neighbor's six year old son. The gearing on the three-speed I bought was ridiculously low even in the highest gear, and the seat post was far too low for me. The six year old loves it.