When I ordered the LED trunk lamp, I expected a full fitting to replace the original boot lamp but the part is an LED lamp to replace the standard filament lamp within the original fitting. I checked the Honda part number using Google and it brings up the LED trunk lamp upgrade from a number of Honda parts suppliers, so think with them also it’s just the LED lamp part that is supplied, rather than the entire trunk light assembly.
It’s a simple job to swap the LED lamp in place of the filament lamp. I wonder if the higher price listed in the Honda accessories brochure includes a charge for dealer fitting. It was still a relatively expensive part for just the LED lamp and, as others have stated, there are non Honda LED lamps available at much less cost.
It does improve the boot illumination dramatically and I notice that on the new HRV, LED boot lamps are standard, there being two, one on left and right hand side of the boot. It strikes as penny pinching not to include the LED boot lamp as standard on the Jazz, particularly as the interior roof lights are all LED.