Found my rear level sensor for the E class xenon headlights (seperate thread ) . Whilst the car was in the air I snow foamed then jet washed the underside , then did the same to the clk as all my cleaning gear was outside and set up .
Had the tiny little race silencers welded in. Made a big difference, much to everyones surprise. Most of the background hum is now gone, I would say 70% better. If I had to do it again I would go for the 5 inch rather than 3 inch ones but I am a happy chappy.
Also carried out some rust prevention/treatment on the front right arch.
The front under trays where missing when I bought the car and they make a BIG difference to under body corrosion.
Before:
Wire brushed:
Treated and painted:
Dynaxed:
Tomorrow, other side!
You would be well advised not to use a Chamois. Get yourself some decent quality Microfibre Drying Towels
It also makes the job a whole lot easier 
+ 1 on that , big thick microfibre towel will last a long time...
I see, those front two do quite a lot of deflection I guess. ( purely based on seeing a Karcher blast backwards)There are three main panels underneath, one under the rad pack, one under the sump, and one that goes back past the gearbox:
Like this:
My front two where missing and the bottom of my rad support is all rusted. My wheel arch liners have always been there, as you can see from the pictures, they are pretty clean behind the liner, its the main bit in the middle that is rusted.
I normally use rust treament (kurust, deox gel etc) but I had had run out, so Just wire brushed, degreeased and hammerite straight to rust. As you say it may need re-doing in a while, but its covered in 3/4 layers of Dynax UB a swell.
Dynax UB is a under body wax with some corrosion prohibitors, but its main function is to form a barrier between water/salt and the bodywork, so its rust neutralisation properties are limited.
The front discs, hubs and wheel bolts where spotless when I did the discs 2 months ago, now they are covered in surface rust, all becuase of the HUGE amounts of salt laid down this year and then constant wet weather. I am quite surprised how much damage was done in a short period of time.
It is never going to be concourse, but I am trying to keep rust related failures at bay, I have already had to repair a section of rear brake line.
