@ss80 Let me try to lay the facts in front of you for each of your thought.
Buying a used Daewoo matiz- 1.Sourcing Original spares:-
Car model from a company which has been defunct for more than a decade in India. The dies and moulds of most parts are scattered and have not been usually used (or have been scrapped) . The drawings of parts are lost / no longer available. Sourcing from First gen Matiz parts from korea is another matter.
Result:- Original Spares are NOT available (and cost a bomb if available to actually source and fit into the matiz) 2. Changeability of Chevrolet parts with Daewoo Matiz
-Except probably the Side mirrors , Door handle and Interiors could be changeable. Rest all are different. You take the engine, Hood,Cowl, Front bumper, Head lamps, Front Side fenders , Door Panels, Hatch Door, tail Lamps , Rear Bumper, are all different.
Result:- Possibility of changing parts exist more in Engine , Transmission and exteriors, all of which require original spares (with extreme luck) or managing with jugaad.
Attaching pics of both for a better understanding. Buying a used nano:-
Depends if the car is in good condition. It is a well engineered car. you are replacing your old M800 with it, so in most safety,space and vehicle quality parameters ,you are actually upgrading. If you get a good deal, buy it.
I would bring in another option as suggested by @indian_mustang. Buy a new nano . The 2012 version is an upgrade to the earlier one and has beige interiors and with year end scheme , you get music system and alloys etc thrown in for free. Check out the tatanano website and test drive at nearest dealer.I can send you the ownership cost calculations. If it makes sense, then buy a brand new one. Don't forget to throw a nano party for TAIans.