As we've moved on to van floors let me tell you of my experience. Must you? (Sigh) Yes.
I have had two vans, both from new.
1. 2006/56 1.3 Doblo with a 400 tank which I occasionally overfilled and flooded which due to being on a sloping drive filled the footwells with water!
The only protection was rubber matting laid on top of the floor.
Sold in 2014 to Dan the Man who in turn sold it on this forum in about 2018. Last I heard it was being used as a 'pool' van around 2021.
2. 2012/12 Hyundai iload.
As you may know I had a prang in July 2023, bought the salvage and put it back on the road.
Originally it had ply and wisely or unwisely Dan the Man did as I asked, painted the ply floor with marine varnish and covered it in rubber flooring.
After about 5 years the ply started to break up under the floor but being me I just ignored it as the rubber was intact.
At the time of the crash I thought as it was sat in my drive for a couple of weeks as DtM got the bits to repair it I might as well re-do the back.
Upon stripping the tank, frame and rubber flooring the remains of the ply were lifted which entailed a dustpan and brush and vacuum cleaner!
The original painted surface had a few lines of surface rust where the floor was raised, a little bit of surface rust around two of the frame bolt holes through the floor and a bit at the very back where it got scuffed.
I sanded it, put on a primer and protectakoted it by hand brush giving two coats. Then I bought two cheap rubber oil trays with 25mm raised lips which almost perfectly fit between the wheel arches.
All is good and my van is now in its 13th year.