I got my Z through Bonsai - you really have to watch out for hidden charges - they will try to sting you for the pre-SVA, fuel, etc etc.
The "On the road price" they give should be fixed though which includes tax and duty.... the SVA I never even worked out how they charge for (its more than the T&C) and also their definition of "delimited" is sh*t (your car will still be limited)
Not impressed by them - wouldn't recommend them - don't use them.
Krumble.