The water drains on the sunroof are draining properly. The rear seal for the double dual doors seems ok. My driveway sits at an upward angle. It’s steep but not to steep. I parked her for a few days and everything was dry. So with it sitting in the driveway and it raining it now has water in the spare tire wheel well again. Every place else inside is dry. Maybe the rear double door seal needs to be replaced? I’ve read about the metal body panels sealant going bad but I would think any water getting in would be from driving as those areas are sheltered from the rain when the car is parked.

Thoughts?

 

Did you check all 4 roof drains? The two in the front often get all the publicity because they drain down onto the FRM. But there are two more in the rear of the roof frame.

Another possible culprit would be the roof antenna gasket.

Maybe time to pull the headliner down and check some things?

 

I poured water down all four corners and it drained as expected. Even made the gurgling noise as it drained. I tried to run as much water through as I could to see if any water would drain into the wheel well. Nothing. So I figured I’d see what things looked like after it rained and let the mini sit.

I think I might pull that rear tray out that holds the third brake light and check the seals.

 

Oh right, I forgot about that part… that would be my next spot to check, too

 

I had the same prob a few years ago. It was the antenna gasket, I used a bead of black silicone sealant that matched the black gasket. I've re-applied once since then.

 

UPDATE- The center gasket that’s attached to the rear door on the drivers side had a small amount that was damaged. I attached some replacement material with black rtv. It been sitting overnight in garage so I’ll inspect it later today. I did replace the antenna gasket when I replaced the antenna in 2023 and did the third brake light around the same time. I’m really hoping it’s just that small damaged piece of gasket but will know soon. Thus far all repairs have been very minor but that gasket is over 550USD new.

 

another Update…

I noticed the gasket for the third brake light is cracked in a few places… I’ve not ordered a new one but I went ahead cleaned and black RTV’d them until I can get a new gasket. So far no leaks but it’s not been raining much.

 

Ok it’s been several days and I don’t see any water getting in this far. Fingers crossed of course because you know minis.

 

Although we have different models(R58) I discovered water coming into my hatch and pooling in the area under Jack/tool tray
then source of the water were the tail lights

i removed the tail lights and applied Dum Dum Strip Caulk between the body and the lights
reinstalled the lights and no more leaks

that might be the source of your leak
worth looking into

 

I was thinking of that too but wanted to eliminate the leak using deductive reasoning. So far the leak has been fixed. So far… lol… but I want to replace my tail lights with nice LED lights that aren’t in the pattern of a British flag.

ill be looking into maybe using the product you mentioned over the black rtv for removable items like lights. Thanks 🙃

 

nice to learn about the Dum Dum Strip caulking. nifty.

 

31MARCH2026 UPDATE:

ok it is still leaking. So a few days ago I pulled the third brake light tray out. I broke it down and then cleaned it. Then I redundantly sealed the damn thing with black rtv. I closed all the holes and made it into a giant plug that allows no water to get past it after being installed. I sealed everything even though by design it’s meant to have drains.

the sunroof drains work perfectly. They are not leaking at all. They drain as designed so they are not the problem.

I pulled the rear door seal off, cleaned it, cleaned where the door seal presses onto the body, then I ran a very large bead of silicone grease on the metal and inside the rubber gasket. Then I pressed the damn thing into the body and then ran a bead between the body and gasket and rubbed grease on the gasket surface that meets the two doors. Then I greased up the rubber door seal that is attached onto the one rear door. It finally rained last night and I checked on the tire well. There was just a very very small amount of water on the bottom. Like as if I took a window sprayer and did one or two sprays.

i might rub more silicone grease onto the door gaskets again.

I’ve replaced the antenna and used an OEM gasket and it’s bolted on tight. I rechecked it when I pulled the third brake lights tray.

I’ve done a ton of work on this JCW R55. It’s broken down on me many times and I’ve always just taken it in stride and over engineered repairs just so I know the work was done correct and with better parts when possible. But this is beginning to **** me off to no end. As soon as I get my diesel cruiser back on the road the mini is going to get pulled apart for the stereo upgrade and other mods. It better not fricken leak when it’s done. My cruisers being blocked by a couple vettes and another two race cars that are being worked on in the back so I’m unable to break down the mini until I get my cruiser out.