Well, got done with engine mounts, engine shocks, trans cooler lines, and vacuum modulator on the 300TD last Friday. Vibration free and shifting is great! While the car was up on the lift, I started poking around and found soft undercoat on the bottom of the car, on the left side of the drivers floor, where it meets the inner rocker. Pushed harder and heard crunching noises. Pulled the floor mats up and found that all there was was undercoating in the "valley" that is there. Poked around on the other side, and hard steel. Poked around the entire bottom, wheel wells, etc. The rest of the car is fine at this point. I am counting my blessings on that one. The rust is localized and was very dry and scaly, which tells me it rusted a long time ago and has been dry a long time. Removed the plugs underneath and was able to examine some and the metal is fine. So, since it was minor, I POR 15ed the area, and am just going to lay a little fiberglass, more POR 15, use spray chipguard underneath and call it a day. Since it is not structural, it should be OK. My MGB that I just sold had a similair repair 30 years ago, and is still sound! Not the best way, in my opinion, but it does work. Only thing I can think is that the undercoating got some moisture behind it in that area a long time ago, and the moisture had nowhere to go. I am going to blow all the drains out just to be sure though! I assume that the cowl drains, and sunroof drains empty into the rockers and drain through the rubber plug with the holes in the bottom middle of the rocker. Is this correct?