They may have... in-game there isn't the antenna I don't think. Not that it would be impossible to add. But on the P-38 there very clearly is.

The tail warning radar was found on most US fighters by late 1944; on the P-51, the antenna was mounted midway up the vertical tail, about six to eight inches back from the leading edge. P-47s had a similar installation.

If you look at photos from the period, you can pick them out fairly easily.

cheers

horseback