I used these:

https://www.amazon.com/dp/B0091U4T9I (I've purchased from seller Horne Mazda Avondale on Amazon multiple time for various parts over the years and never had any issues)

Curt cargo basket

https://www.amazon.com/dp/B004O844DS

There's a GREAT review posted on Amazon for this carrier basket by a guy named Andrew that gives a bunch of info about how to prevent rust (using silicone and swapping out the screws - he includes the numbers for them too!) and lots of pics as well. https://www.amazon.com/gp/customer-reviews/R1K2J0X7S12WMP

I love the Curt carrier, it's solid and I've never had any problems with rust (followed the reviewers instructions). I did get the corresponding extension piece, and in my opinion it looks a a smidge long on my roof but I love the extra space for camping and trips and I haven't taken it off since installing it in 2017.