You're right Frank, you don't need one, you can do it yourself. Thing is, a solicitor knows all the tricks of the trade to make sure you get recompense and is someone on your side. It also sends a message to the other side that you mean business.
Kevs problem would be though rich is how does/can he prove it was ok before adding the stuff. He could have bought the truck like that. There could have actually been an issue before the stuff was put in and the egr cleaner actually just finished the rings/ Pistons off.
I had ham belt years ago that snapped 100 miles after it was fitted and ruined my engine. Only a mark 4 diesel escort. I had no chance of getting a penny.
If kev does try it I hope he does get somewhere.