I should have solved it immediately as Rodrigo Auto Design's website address can be read in the shadow below the car in the puzzle picture !
Oh dear, that's terribly careless of me and I can't imagine why I didn't spot it. Maybe I used the wrong image..
Solved it is.
I've checked the images on my computer and the only sign of the writing that you can see on my puzzle picture is a little squiggle on the wheel!
There's no sign at all of Rodrigo Auto Design beneath the car, nor can I see it on the puzzle picture on this computer, though I can on my computer at home..
I'll have to re-adjust my contrast again!