At present, such an accessory is not available via Pico for automotive applications.
That is not to say that there will not be such a device as new accessories are always under development.
Could I ask, what are the frequencies you wish to detect in your country?
(Remote Key Fob transmission to Vehicle Wireless Receiver)
Would you be looking to simply identify the frequency, the amplitude (strength) of the signal, or purely to confirm a wireless transmission event is present when operating the Remote Key Fob?