"I have the car."
I wrote: "C'ho la macchina" and was marked wrong. Well, I live in Italy (Tuscany), and I can tell you, that's what people actually say.
I have both heard it and seen it written. And yes, Tuscany is beautiful; but the political situation is appalling.
C'ho, c'hai, c'ha and so on are considered slang forms (they actually go against Italian rules, which allow ci to be elided only before i and e), and although widely used, "ciò (che non è ci + ho...) non vuol dire che tali usi siano ammissibili o tanto meno consigliabili nella prosa sorvegliata e negli usi standard dello scritto" (quote from http://www.treccani.it/magazine/lingua_italiana/domande_e_risposte/grammatica/grammatica_060.html that contains a grammarian's opinion). In other words, it's substandard Italian and you should avoid it outside colloquial contexts.
P.S. The political situation is much worse in the rest of Italy...