What side of the road do they drive on (part 3)?

Leaving London, the overnight bus was on the left side of the road.  This must have been a bit awkward because the driver’s seat was also on the left.  Then we arrived at the chunnel staging ground around midnight or so.  We were in a line for 1:35 am departure, and the sign indicated that we would board the shuttle about 25 minutes before the scheduled time.  So at the right time, the driver loaded the bus onto a tunnel-like train.  I picture it a bit like the Amtrak car train that can take your car to Florida. 

For the chunnel trip, about a half hour, the driver did not drive at all on either side of the road.  We were conveyed, along with other buses and vans. People were able to get out of the bus if we wished and walk around the inside of the shuttle.   Then when the conveyance reached France, the driver started the bus and drove off the shuttle -- to the right-hand side of the road.