Dog seat cover for 2017 BMW X3

My 55 pound herding mix refuses to sit down in the back seat and gets tossed around when I make turns.  Can someone please recommend a "hammock" that:

-is very durable, will last for years

-is grippy enough for my dog not to slip

-will fit well in my 2017 BMW X3

Thank you!

Min. Budget
Max. Budget