As muk1 wrote, some of the lamps are quite tight and specifically the length of the bulb is critical.
I used two LED bulb types:
In majority of the lamps I used a power W5W (T10) led bulb with 5 leds (see the picture). That was 12 V/0.9W but unfortunately "no-name" product from a local car supply store. This bulb type fitted to the foot-well lamps, to the trunk and to the door lamps and for the general light bulbs in the ceiling domes.
In the reading lights where the length is tight, I used a small Philps W5W "Vision LED", 12V/0.6W, and even in the rear dome that seems to give quite bright light even though the led is only at the end of the bulb.
In front for lamps above the make-up mirrors: Philips Festoon C5W power LED (lenght 43mm), 12V/1W (see picture 2). In the glove-box: Philps Festoon C5W power LED (lenght 38mm), 12V/1W.
Also as muk1 told, the original cabling in the rear doors were quite short, so I even have to make small extension cables to manage the installation. For the extension cables you could use some conector "raw material" from electronics componts stores, see picture 3. You must then cut the connector so that they contain only "two pins (both male and female end)" and then some soldering is needed.
