You called for a 'Good 'Ole Boy' or 'Average Joe'? Well, here I am!
First lets all have a beer or two, and cool down the radiators a little bit. I will try to answer as many of these 'gripes' as I can.
bradfordro, if your trip odometer is working you know then that the speedo cable that comes out of the BACK end of the transmission is working. The brake sensor that belongs on each front wheel grounds the light in the cluster. Why this does not make a Mercedes a weird automobile, these are both very straight forward designs. In case you did not know, a Volkswagen is also a german automobile, with a large number of vendors making parts for both automobiles (Bosch, Hella, ATE, Girling and many more). Perhaps you would be happier changing spark plugs on an American car, or wrestling with the rear brakes of a General Motors car! Or how about a Kia?
Josh, yes you have to watch that the brake sensor does not touch the wheel or disc, that will make the pad light glow (if that is the light that is on). And yes the brakes are straight forward and have only a few changes from model to model. The Germans do things different from the Japanese who do things different (and usually better) then the big three in the USA.
The 190 series was designed as an entry level Mercedes-Benz, and many Technicians would agree it was not their best effort, but most would agree after those first years, the 190's became a very good car. Especially of taken care of by a well trained technician, with access to factory parts and manuals and ETM's. I have have cars in both excellent and terrible condition, and you can tell the car that has been properly taken care of, and by your comments, I would thank you to keep struggling with your own car, and buy the proper manuals so your 'inexperience' will not be so readily apparent.
JDEN, sorry I don't have time for your observations. I also like Toyotas.