Hi Redarrow,here's one offer
, the seller also has fully insulated connectors for sale, yet four of them won't fit, so I found it easier to put shrink hose over every other one.
I have a quite standard electronics soldering iron with a 3 mm tip and used Sn60Pb38Cu2 wire, the electronics one with flow agent inside.
The LEDs are small, 3 mm I suppose. One is used for the backlight, the other for the switch. Later cars have a "boot open" light in the instrument panel, so there's no need to fit this into the switch housing.
As the switch actually draws power from the brake light connection, it already works in the way you proposed. This prevents opening the boot accidentally while doing 100 mph on the Autobahn, simply because some nutty passenger can't keep his fingers to himself.
I got a kit from eBay
as well, yet this incorporates a lot more than you will actually need, for example a relay, which won't be needed if you utilise the one for the cigarette lighter like I (non-smoker) did. This makes cabling a lot easier. I used the spare relay for the DTRL mod later, so not a waste
PS: More mods to come, no question