Child Car Seat for 2003 325CIC

[Dutchcourage]

I am having great trouble finding a forward facing car seat solution in my 325 convertible. My son is 2 years and 2 months and about 30 pounds.

I have tried several seats, but the shape of the bucket seat in the back makes it very hard (impossible?) to fit a car seat. All the car seats I have tried so far are are too tall and sit against the headrest (as the headrest is part of the roll-over pretection system, it cannot be removed). As a result there is a large gap between the car seat and back rest in the car. There does not appear to be a way to get these seats properly installed.

Does anybody know of a particular brand/type car seat that is sold in Canada that fits in the back of a convertible 3-series? All tips or suggestions are greatly appreciated!