Check for this part of the loom halfway along the OS sill. My other starlet has thia and wasnt fitted with an amp as an extra. And this part of the wiring comes with the amp im sure, but should plug and play with the normal GT loom
Yeah it was more efficient a few years ago when the pound was stronger and all that. Suppose if you were keeping the car for a few years it wouldnt be too much to lose. Id love to import a Chaser V