Not a very obscure make, perhaps, but you could say it's better known for what it isn't than for what it is...
OK, Rookies -- your week is up.
Experts?
BTW, at least one reference has been made to this car's builder in AutoPuzzles before...
No Expert action either, huh? And this one could be easy if only someone tried...
OK, opening up to all now.
It looks like an early Royce 10 HP - and it is not a Rolls-Royce
That's exactly what it is (and isn't), sir! Well done!