In the two years I've owned my DB9, I've read many instances in which owners have been locked out of their cars with dead batteries, lock failures, and no access to the boot.
While I'm waiting for my replacement Convertible Roof Module to arrive, I can't get in my boot either, and I get paranoid if I leave my Aston for too many days not connected to its battery tender. Yes, I know I could use alligator clips to connect it to the + terminal and a ground under the bonnet, but it's messy and what if some mysterious Gaydon Gremlin won't let me open my door or bonnet?
Anyway, I simply picked up an extra connector for my tender and wired it to the + terminal and a ground under the bonnet, then routed it under the slam panel, finally tucking the connector neatly behind a grille slat. Took less than a half-hour, including drilling a small hole through the + terminal cover for the wire and removing and replacing the three thousand or so screws holding the slam panel...
Now I can connect my tender at either end of the car, and can charge it even if the doors and boot are locked and the bonnet shut.
I'll sleep better tonight :-)