Just take a break!
If you can't find the problem just take a break doing something fun. Get your mind off cars for a while. Go to the beach. Do something crazy... This is what Kent does..... he admits this was taken a "few" years ago... :-)
Problem & Solution
Common among these chassis:
R107
W114
W115
W116
W123
W124
W126
R129
W140
W201