How Long To Heathrow

Hi All!
We are going to LHR for a few days in January and are returning Jan. 8 (Sat) morning. Our flight is at 9:30a. We are in UC and the Virgin Limo is scheduled to pick us up at Claridges at 6:15a.
1.) Is this enough time to get to Heathrow and enjoy the clubhouse?
2.) What exactly is "drive through checkin"? I have never heard people speak about it on these boards.
We are going to LHR for a few days in January and are returning Jan. 8 (Sat) morning. Our flight is at 9:30a. We are in UC and the Virgin Limo is scheduled to pick us up at Claridges at 6:15a.
1.) Is this enough time to get to Heathrow and enjoy the clubhouse?
2.) What exactly is "drive through checkin"? I have never heard people speak about it on these boards.