I think all the new ones are rack and pinion? However a similar fault with this and the steering box of earlier cars could account. A decent garage and a full alignment kit will find this, although there are simpler ways, and it could be sorted out in some garages at home.
Basically, I doubt straight ahead, is actually the box or rack centre. With a box equipped car, you find straight ahead on the box (pretty easy) and then move the clamp on the drag link so the car goes straight when the box is centred.
With a rack, the ends need to be the same length. Usual way they get displaced is a garage fits new tyres, offers to do the tracking, and only adjusts one end. With this the steering wheel position moves.
Given the problem though, I'd certainly jack up the whole front end and give it a good inspection including measuring the exposed thread length on the steering rack ends.
