where to place alarm emitter

i have a steel mate 888, i have a 1959 model car wich although very customised it is very period with no modern parts showing. i was going to fit the emitter iside a sun visor but i cant get the cable to run through the A pillar. offcourse this car is steel everywere, steel dash, bumpers, grill etc i would like to keep as much range as possible, the emitter is like a small box with a 3.5" antenna and a long cable with a 6 din plug. in the instructions it say to mount it 10cm down the windscreen from the top of the glass so i guess the emitter doesnt like metal but i cant have it on the glass.

It can be mouted near metal.  It will just not give you the most range when mounted near or on metal.  The chassis of the vehicle is grounded.  The emitter is a radio transciever, it sends and recieves radio waves.  It will work just like your car radio when you remove the antenna mast.

i might just test a few spots, just sitting on the floor with the car in the garage it seems to transmit to the reciever/remote in our aluminium clad house, i might get the missus to trigger it while i am up the street.