Sonic Strike - "Single player expansion" ?

[JasonAlaska]

On the Sonic Strike order page it lists the description as, "

Head back into the arena for more autodueling action!

Sonic Strike is a single-player expansion for Car Wars Sixth Edition that comes with 40 ALL-NEW cards to add to your collection. Use sonic weapons to bring your opponents to a screeching halt. Say hello to six new Crew members and take advantage of their unique abilities. Need to grab a bite? The new Grilled Cheese Dispenser will help keep you going until the battle is won. Make the arena your own with Sonic Strike!

This is an expansion for Car Wars Sixth Edition. It is not a stand-alone game.

Is this correct? Is it a single-player expansion? I don't see a mention on Rules Insert for the product.
Thanks!

https://carwars.sjgames.com/products.../sonic-strike/