I was reading these last few comments and thinking: I can imagine, in fact I bet, that once Chris drove his E9 through river water (same spot as many others did I might add) and NOT salt wintery snow or sea salt …. Once Chris got home and after grabbing his favorite Pinot , he meticulously (once again) got under the car and wipe it off, inspect, and polished the lines, when the dust of 6 months in the garage has been washed off. While at it, he made sure the yellow factory hand brushed marking on the CV joints are still intact and ride height of the shocks look all even, and look at the condition of the anodized , or zinc plated clamps.
It is not the salt water or rain, or river water that does the damage! It’s how you take care of the car after(or before) such types of driving. Cars were designed to go through elements. I know what you are thinking , yes it is an E9 , it was rusting before it was even assembled. But if so then this should be a moot point.
I am sure there will plenty of pictures showing the condition of undercarriage! If I am spending six figures on a classic car as my toy, I go beyond of the question if this car has ever been driven in rain , snow , or river for that matter. In fact it would be naive of me to think otherwise for a car that is over 50 years old. That reminds me of a friend that once wanted to sell me a property with prospect of a great future in middle of the Florida Everglades.That was 42 years ago , and we are still good friends….