PHP Interfaces and namespaces

When developing a package or application is there a best practice, FIG standard or community consensus on where to place class interfaces in consideration to namespacing?

For example should we:

• App\CarInterface
• App\Cars\Ford
• App\Cars\Toyota
• App\Cars\Tesla

Or should we:

• App\Cars\CarInterface
• App\Cars\Ford
• App\Cars\Toyota
• App\Cars\Tesla