Hi Tony
LOL my world as well tony.
I now use this procedure.

Code read and log 'every' code on the invoice and print this also.
Clear down short road test see whats returned.

Evaluate the owner the car and condition/miles.
You can no longer clear down and 'not' tell the customer,i consider all intermittent errors to be live and explain possibilities and possible issues that can happen.

I get the customer to authorize repair of returned codes and they now know intermittent codes may need attention...

All my invoices now show every code logged and which ones returned and which have been diagnosed and fixed...i now number them for customer ease.

We explain that intermittent errors can be live and car now needs to be monitored.
This ensures you don't get slated for my check light is back on!!

I am seeing C4 cars with 8 errors and all are live.
I kept this car for 2 weeks and they all returned.
Most are diesel flow and pressure solenoids sticking and ping light on.

Whats the cause poor maintenance and contaminated fuel/pilot error!

I write the time started and time finished on job card and try to charge all time..i neither made the car or sold them the car or abused the car.....if i don't do this i work for nowt all day!

Simon