They need to be for closed rails, I am looking at the,Thule 961 Wing Bar with 4 Thule 591 Bicycle carriers Pro Ride, if anyone has any opinion on these or what may be a better option I would like your views.
Thanks.

Wing bars are good. The 591’s are solid and work well, they have been replaced with a newer version, 598, which reviews say is better. I have 591’s and wingbars on my car which have been on for around 70k miles in 3.5 years and they are as good as new. They (3) are used 3 or 4 times a week.

591’s are brilliant (or the latest version). Not particularly theft secure, but for convenience they great. If they’re going to be a permanent or semi permanent feature on your car then wing bars are pointless. Any aerodynamic and wind noise benefit wing bars provide will be wiped out by the racks even when there are no bikes on them, so maybe save your money and get the cheaper aero bars or maybe just rectangular section bars?

^^^ my empty racks and wingbars are significantly quiter that the aero ones I had previously. Maybe depends on individual cars or something

I have used 591s for years and they are great, but I recently bought a 598 and the design has improved over the 591 in almost every way. Better clamp design with padded rubber, torque limiter, ratchet wheel straps and wider channels for fat tyres.

Cheers guys

598 and Wingbars here. Very quiet, very stable. Easy to put on and off as well. Recommended.