250l 
You were sitting on a gold mine.
They got me the stuff as they are a van importer and used it on the vehicles in preparing them for the show rooms - you'd be amazed at how mucky new vehicles get after coming in on a boat and sitting on the docks for up to six months!
It was hard work spread over 6 weeks. I learnt a lot from it.
Mainly get someone else to do it and take a bit of profit!
I think that most manufacturers spray their new cars with a wax protective coat as PSA does. Once a new vehicle was sold, our valleters sprayed a TRF mixture onto the body and immediately jet washed it off. This was always done in the cool of day in the summer, usually first thing in the morning.
I still have a 25 litre barrel of TRF. I used it on my first conservatory clean and paid the price of letting it dry. It took me 8 hours to get the stuff off with Jif and very hard work. The side that was on the boundary with the neighbours conservatory was impossible to get to because of the small gap, so I left it. 7 years on you can still faintly see the TFR stain on the top panel.