A rental agent told me that the spouse is covered if they're both listed on the same policy back home.
Call the customer service number. If you open for the insurance from Fox, you probably will not be able to drive as you won't be covered in case if a issue. If you didn't and are going with you on insurance that hopefully covers you and the rental car, you should be fine. I would still can the Fox's customer service number to make sure.
Thanks! Your answer is awaiting moderation.