You can’t . That’s the joke. If you use car play and ask Siri to find a local destination or a celebrity birthday, the functionality will be refused since the d

You can’t . That’s the joke. If you use car play and ask Siri to find a local destination or a celebrity birthday, the functionality will be refused since the driver is assumed to be operating the car and thus blocks internet search, even though it will search in Apple Maps which obviously isn’t cached on the device