Thanks for help and answer. I did remove radio and the only thing on
back is the 2 modular plugs which I presume one is the power cables
and the other the ground and speaker wires. They are all bound in a
loom and terminate at a modular plug into the radio. I pulled them out
and none loose. Also the antenna jack was firmly seated and also not
loose. No ground wire on back of unit.There is a black wire in the
wire plug that may somewhere in the harness lead to a ground somewhere
probably a common one for all components of low voltage in car. Also
no adjustment screw since it is digital radio and factory stock
supplied to Toyota. The antenna to specify is a 18-21 inch single rod
screwed onto mast mount or wheel flare in passenger front. It is black
coated with what seems to be a wire coiled from bottom to top under
the black and usually found on all factory cars. It is a radio
antenna no other communications. I know atmosphere, weather,
mountians, etc. plaque reception but this is beyond that and compared
as I said in alot of field testing by me compared to otehr vehicles
and also past performers. I am at a standstill to as why. Radio is
fairly easy to remove with 4 screws on bexel face plate with a number
6 hex wrench and 4 -10mm screws under and slides right out. Booster
installed did do nothing., Not worse but not better either. In cities
may get along fine but in the rural and small town areas where i live
work and play is another story. Any suggestions for anotehr antenna
that would fit the screww on stub mount to improve it. Nick