[carlosz]

the VW harness has worked for me in the past with a minor modification, the adaptor is wired so yellow wire is switched and red is memory, if left this manner your radio will always remain powered with or with out key in ignition.
to correct this concern, you swap those two and test, on occasions I have removed from pin locations to set properly, and on other instances I test and simply wire connector yellow to radio power and connector red to radio memory.

 

[carlosz]

now a days radios have 2 power outputs, one interrupted for power antenna, (lowers antenna when using other media) blue white stripe and one for amp turn on (blue), sometimes both are provided in the harness kit, but often times I use the blue white after testing.

 

[carlosz]

1994-95 Land Rover DeFender 90 Car Stereo Wire Colors and Locations

www.the12volt.com