I had the same issue with my rear U shaped parking lights not working and figured I'd share how I fixed it in case someone has the same issue and is brave. Not having the large rear parking lights on was annoying to me; the small ones did still work as designed, so the rear did have lights at night but they are very small. Part # 51247453841 is a microswitch located at the left hatch hinge (see picture of left hinge). The switch has a tiny orange rubber cap with a tiny rod in it that is activated by a mounted arm when the hatch closes; the cap and rod look very much like a tiny pencil tip (see picture of the switch I removed; switch mounts from right side of hinge with two prongs and the metal pressure-mounted 'nut' panel with two holes are on the left side of the hinge and hold the two tiny prongs via pressure). My switch had gone bad; the orange cap was visibly off center and bent, I suspect just from eventual wear and tear. I found the part on ebay for $41, it came from overseas and took a month to arrive. Gaining access to the switch by partially pulling down the back of the headliner (use fingernails to pull out the two plastic headliner pins near the rear as shown in picture) is the best way I could get to it. There must be a better way but I don't know it. I used a bungee cord to hold the headliner corner down as this is a very very tight space with very little room to disconnect and remove the old switch wiring and to route the new one. There is also a small zip tie high up holding the wiring to the hinge. Not for the easily frustrated. I did replace the zip tie with a new one I had. This did leave a crease in my headliner near the rear-most left side window (see pic above window) but the lights now work.
