Avistart 4200 - antenna placment

i installed a avistart 4200 w/keyless and remote start, but the range sucks bad, im used to my compustar where i could start my car from in a mall or down the road, this thing just sucks. its wierd, sometimes i can start it from in my house, sometimes not, its like its a directional antenna, some angles work better.. i think.. the manual says nothing about the best way to place the antenna, so i did it in horizontal in the upper corner of the windshield driver side. now sence its a omnidorectional antenna, i figure, i mounted it to my mirror pointing strait down verticly level. if this works like other omni antennas, it should have worked better, but not really. anyone have any ideas/tips?

upgrade to the XHF Plus antenna.... the HF+ antenna was a weak point with these units..... Kevin Gerry

Certified Electronics Technician

MECP First Class Installer

Owner/Installer

Classic Car Audio

since 1979

thanks

hey anyone know where i can get one? i already googled it and checked ebay.. i dont wana go to a local shop any pay out the ass.