Mine is Vauxhall Astra.
I got the Saris Bones 3 bike and purchased from Go Outdooors who WERE very much over-priced but as promised "price-matched" another supplier.
The 2 bike does have one advantage..........having just one arm it will sit better/easier that the 2 armed 3 bike model. A bit like a 3 legged stool will sit better than a 4 legged chair.
I do rate the Saris and would recommend it.......unlike my previous carrier I am not nervous & worried that it's moving.......it is solid.
I got the Bones 3 from Go Outdoors also. I paid £99 for it a few days ago with whatever deal they had on and a membership card and 10% off (or something like that).
I have a Citroen C2 VTR, which is quite a small car and, although the Bones 2 would probably be more compact fit on the car, the Bones 3 is better. The problem with the Bones 2 is that the one arm you talk about that sits on the windscreen exerts all the force at one point, the two arms of the Bones 3 spreads the weight more evenly. Not that there's much weight on the windscreen anyways, most of the weight is on the bumper. I'd like to do a side by side comparison of the Bones 2 and 3, but I don't know anyone locally that has the Bones 2.
*UPDATE* I emailed Saris about the size difference between the Bones 2 and Bones 3 and got this reply from Harvey Eustice:
"The tube that the arms and legs rest on has a difference of 5 inches. The arms and legs are longer by a few inches. Realistically, though, you won't notice a difference except for the arms with the cradles being longer" (Holds 3 bikes instead of 2).
I have also toyed with the idea of swapping the position of the upper arms and lower legs. You will notice,
@Dave7, that the upper arms (that rest on the rear windscreen) sit the furthest outward and the inner legs (that sit on the bumper) the most inward. If I swap the positions of these arms and legs, I would imagine that the lower legs that sit on the bumper, if spread the furthest out, would make sturdier base as when they are inward. The way the Bones sits now is like an upside down triangle, if I change the position of the lower legs, the rack will be a pyramid shape, and we all know what pyramid shapes make. I doubt it would make that much difference, and I'm sure the designers of the Bones knew what they were doing, it just makes more practical sense to have a wider base at the bottom than the top.