Thanks for the comments everyone - it's appreciated. The hole I found is indeed a drainage hole, which is excellent!

I did a lot of exploring today and came up with some issues.

I began with the hosepipe-down-the-passenger-side-drain scenario first. The rear passenger footwell immediately filled with water, channeling down the plastic wire cover. I didn't spot it initially. Damn stealthy water leak! I had all the carpets removed that side, and also took the lower dash panel off too for extra access (I really must replace my heater blower too - thing is starting to squeal its nads off).

Following this, my wife's hairdryer (ssshhh!!) proved extremely useful to ensure all the flooring was then thoroughly dried. It seems like the protective layer on the floor in the passenger side rear footwell is starting to crack and soften from moisture getting in now, although there's no signs of rust there yet thankfully.

So it seems like there's a leak coming from right in the corner of the bulkhead somewhere. Also, one of the rubber pipes that travels through the bulkhead has a rubber grommet that's all wasted away, so you can see daylight from under the dash. Not a lot of daylight - and the leak clearly wasn't coming from there - but it's not going to help matters, so I'll be re-grommeting (yes, I made up my own word) that!

I then got the car jacked up, wheel off, and removed the plastic wheel arch protector. After I'd removed the garden load of compost that was stuffed inside the wheel arch and at the base of the front wing, I could see a lot of extremely damp metal on the inner arch, with some (not too severe) rust forming on bits of it, and some sealant between panels starting to decompose. Looks like my leak is coming from a gap between panels!

Fortunately, it looks like I've caught the rot in its fairly early stages. It, of course, needs sorting as soon as possible, and luckily it's far from fatal at this point, phew! The car is going into (underground, secure) storage in March for about six months whilst I'm overseas (in the land of non-rusty old Mercedeseses - the Middle East. Parts anyone?!) I think I'm going to stop the rot from making any more progress for now, and then wipe it out when I get back and have more time.

For now, I've made sure the inner arch is damn clean (34 years of mud and crap builds up pretty nice!) and also thoroughly cleaned the plastic inner arch liner. I ran out of daylight today so I'll be continuing tomorrow.

A couple of questions following this adventure:

- Resealing the cracked protective lining on the passenger rear footwell: any recommended products for this?

- Any recommendations for sealant to replace the decomposing sealant on the inner wing too?

Also, here's a few pictures (everyone loves pictures, right? )





Battery tray before


Battery tray after


The dent on the wing has been driving me crazy since I bought the car ten months ago, but there's more important things in life to spend that money on (for now!)




On my shopping list too