Qué ves letra
 

Have you had luck with the rest of the song?

I only can give you some hints (these lyrics sound to me like free association technique in psychology)

fiar --> to sell on credit (can I have a beer fiada? I'll pay you on Friday -when I get paid-)

la chapita ---> a crazy woman (from "volarse las chapas" -the wind blowing pieces of sheet metal from a roof-, used with those who are getting bald or those who are loosing their sanity)

porrón ---> in Argentina, a small bottle of beer that has been replaced by cans (but I suppose it's intended as a "porro", that is, a joint)

palomar ---> El Palomar, a district of the Metropolitan Area of Buenos Aires that is 3 km away from Hurlingham, another district where the rock band Divididos was formed. Both are linked to downtown Buenos Aires by train. Besides, in almost every town and suburb there is some "this side of the railroad, that side of the railroad" local logic, with the rich side and the poor side or so, then "cruzar la vía" may mean to downgrade socially or to go to not advisable neighbourhoods to get some fun.