Just watch out for the "buckle crunch" thing. This is where the buckle system (of your Supra) is so close to the child seat, when the belt is plugged in, it can suffer from exploding against the seat in an abrupt stop...releasing the seat etc...
Does your Britax Prince do this?
And does the Prince model seem too Top heavy and not anchored in...ie if you grab the top and pull it, it shouldn't move at all...
We tried the Prince and found that it suffered from both of these issues.
I'd be interested to hear.
So yes, it fits nicely in the bucket sat, but that was it really
In the end having tried 5 or 6 seats, none of them fitted or were satisfactory. We ended up with a Maxi Cosi and put it in the front seat. I have no front passenger airbag, so it's fine to do this. And the Mrs goes in the back...
I'll throw up a couple of photos later...