Go to a junk yard and look for a simular
sized car.
Remove the trunk unlock system.
I don't think you'll need to do much
modification to fit the cable to the
trunk lock,but you'll need to do some.
When you mount the handle next to your
seat,check for fuel lines under that area
before drilling holes.
Use permatex silicone to seal the holes
to counteract rust.

DONE.

I did this once when still living in Europe,but
I used a hood unlock instead,since back then
car makers just started to come out with trunk
releases.

Louis.