My ex iswara used to have the same problem on the tenth years, sometimes difficult to starts especially after a long drive or very heavy jam during hot afternoon, engine can restart upon cooling down for half an hour, battery, alternator, cable, plug all ok, according to the mechanic starter relay is aging, he add in another relay, problem solved, he said common problem with iswara & wira.

Can says same to your City though, but can ask mechanic to check the starter.