I had motor bike plates on my Cougar and they where WELL tiny! I personally loved them as they made the car look bigger and really tidy'd up the front and back of the car.
Admitadly I got pulled once by bobbies on foot but I blagged it as I had my correct sized ones in the boot and said Id been to a club meet the night before got back late and had forgot to change them.
He checked all over my car, my tax, insurance and had a 20m chat about my car and then he just let me go.
Its up to you. I dont mind small front number plates and besides if its just the front if a copper sees you from the front, he's then got to turn around and give chase all over a tiny nimber plate . . . Nope dont think he's gona do that.
French plates will look better but if you like the look of the tiny plate go for it and keep the normal sized one in the boot just incase