I always take pride in my DIY repairs, especially when I see the Stickers on new cars--an average of what, 21,000 $ at 5 years of payments at 450 a month?

The downside is when I make a mistake. I made two the last few weeks and they were pretty humbling and left me exhausted. The funniest thing is that they coincided.
First I tried to build my own center muffler out of spare pipe and flanges to save my self---as it turned out, $150--right here on Mercedes Shop. I thought the unit would run about $300. Luckily--or unluckily--I ran into a friendly Midas Guy who helped bend the tubing and gave me all kind of free stuff for $30 cash--which I had to force him to take.
You just cant compete with the pro's when it comes to exhaust building
I welded and welded and cut and cut, but the thing would just rattle and even after I got it fit--the dam&*( thing missed the key frequency that needed to be eliminated and the car sounded horrible in 3rd gear at acceleration. It sounded home made Add to the Comedy was my jack rebuild. i almost destroyed a hein Werner jack that runs some $400 in today dollars-- I tried to weld the drain plug to eliminate occasional leakage.
It turns out you can't weld in an oil environment. You just can't. Even if you think you have got it clean, it still bubbles up. What made it hysterical was the weld collapsed as i was jacking the car up to remove my lousy homemade muffler--the jack oil squirted out in a Classic keystone Cops stream right into my face.

The two mistakes surfaced on the wrong day when I was sleep deprived. I kicked the jack a nd I tried to remove th exhuast system and got frustated and took it off with a Sawzall. Thats what a bad day it was.

Total cost of my errors was low. But I wasted 3 days and almost destroyed a $400 jack.