In case anyone's wondering, Crew Chief works well with PCars2. Currently, the game only supports the old PCars1 data format so the app is already compatible and fully working (subject to the existing limitations in the PCars1 data - things like opponent tyre selection are unavailable).

When SMS finalise and publish their PCars2 data format the app will be enhanced to take full advantage of it.

Note that this applies to the PC app and the Android app - both should work with PCars 2. The PS4 and XBox versions of PCars2 don't have UDP data output at the moment - this is coming in a patch, apparently.