or if you want to go on the cheap ... go to
www.freeantennas.com
you could make one of those and put it on one of the rubber ducks ,,, and point it where you park your car ...
just a thought
I personnaly have a 15DB omni and a 1 watt amp ( i know i know .. and no i dont have cancer YET... its good i dont post my adress) gets VERY far .. i bought this mini 5db magnet base antenna .. I open my sunroof in my car , let the magnet stick on the top there , and plug it in my laptop , i must have gone about 1 mile or so still works , of course not everywhere , big buildings etc are real problems ,
PS: I have this setup because I have a WISP .... use 24db grids for CPE , all orinoco stuff , ap , cards , cor etc ...