t bar slot horizontal? vertical?

ok- was just curious here because I thought these-the stock ones- were not exactly straight. Like they had a slight bend to them. Just thought I saw a pic of some that had that slight taper to them and you had to put the taper like it was point out to the front corners of the car. A little hard to explain. So I guess my other question is- are these straight do these T-bars have a slight -very slight- curve?