Plot a line from beginning to the end of a trip

Hi,

I have a chart which plots the loading quantity of a truck based on time and trip.

I am now trying to plot a red line which joins the beginning of the trip till the end (before the next trip starts) but have no success.
I have attached an example to explain a bit better myself.

Any help would be much appreciated.

Kind regards,

Hi Crooza,

Thank you very much for your proposal, works perfectly like that!!

Kind regards