I've said on here before I think, but on my Glasgow -> Edinburgh commute I've witnessed loads of crazy things. One woman giving herself a haircut at 80mph in the middle lane (scissors one hand, brush in the other using the rear view mirror to see what she was doing) whilst steering with her knee. A driver watching hardcore porn, another watching cartoon porn. And there was the driver using TWO mobile phones at once.
There was also a guy filling in some form of sales ledger that came close to killing me when I was on the CBR... only a lay by on the m8 Lanark slip saved me. He then called me names and threatened to "finish the job" when I shouted that he could have killed me. That didn't end well for him.
Edinburgh was always far worse for this sort of thing than Glasgow (IME). No idea why.
Regularly saw drivers reading behind the wheel too.