Water leaks in driver's side

[Pruts3r]

Hi everybody!

I am back with the world's most troublesome 75. Yes, it is using coolant again if you were wondering.

But anyway. That not the question of the day:

A while ago I noticed drops of water coming from underneath the bonnet release switch in the car. At a moment the car wouldn't start because the BMW immobilizer got wet.

Plenums are moded and no water builds up there since the day I got the car.

So took everything apart underneath the dash and noticed a lot of water gets in when the car is standing parked in the rain.

Dried everything up. Wrapped the immobilizer unit in plastic and car works great (as far as great applies to this problem child).

We took off the front left wing and saw some places were the in inner wings/panels have smal gaps between them right underneath the corner of the window.
Took the garden hose and presto. Water pored in on the side from high up underneath the window (as far as you can see havin removed lightswitchcluster and everything else).

Closed and sealed everything up and garden hose again. Everything stayed dry now. Great. Looks fixed but I stayed cautious because I know this car never wants to get fixed in one go and today a good deal of rain came down so I thought I'd have a check (still haven't but everything underneath the dash back just so I can check if it worked).
Guess what. The metal was wet and drop can be seen on the side again (behind were the panel goes which holds the boot and bonnet releases).

Any suggestions were to look for leaks? I comes in when the car is parked and it stands in the rain. The corner mentioned befor is closed up for good. No water comes in from there anymore.

Any help is appreciated since I am losing it with the continuous endless problem car