Looks like Bestem has a retrofit light strip for the 929 trunk - for 30 bux! No need for a DYI backyard LED Frankenstein mod, just a credit card. Just might pick me up one!
Optional LED Running/Braking Light Strip for T-Box 929 This LED strip will replace your original red plastic strip on the back of the 929 T-Box. It features two rows of super bright running and braking LED lights. Installation takes less than 15 min. with no additional hardware needed. A hole will need to be drilled under the cover to route the wire (template is provided in this kit). Wires feature quick disconnect plugs so you can easily remove your T-Box. You can also combine your existing 929 tail light with this strip to create more visibility.
Bestem T-box 929 LED Light Strip Kit