Maximising LHR CH on the VS045 to JFK

With the flight booked I now need to finely hone the departure details and would appreciate some input as have never done DTCI.
Driving up from Cornwall early :0 to catch the VS045 LHR to JFK. Leaving car with Crowne Plaza LHR as staying the night when we return a week later on the day flight, so doing a reverse park and stay.
Have never done DTCI and want to know if its worth booking a car from CP to DTCI. If so there are a couple of queries.....
What time to book car?
Which company would you use to get required info in enough time?
Will the driver know where to go?
What happens when we arrive at DTCI?
What time will I get my first glass of bubbles?
Should I forget DTCI and just trundle through the airport?
Thanks all.
Driving up from Cornwall early :0 to catch the VS045 LHR to JFK. Leaving car with Crowne Plaza LHR as staying the night when we return a week later on the day flight, so doing a reverse park and stay.
Have never done DTCI and want to know if its worth booking a car from CP to DTCI. If so there are a couple of queries.....
What time to book car?
Which company would you use to get required info in enough time?
Will the driver know where to go?
What happens when we arrive at DTCI?
What time will I get my first glass of bubbles?
Should I forget DTCI and just trundle through the airport?
Thanks all.