Park your car on the train. There are 6-8 cars per block (more or less, it's been a while since I was on!) with shutters separating each block.
They'll park you upstairs, downstairs or possibly on the cavernous bus/motorhome/massive car carriage.
There's space enough either side to open the doors and get out to stretch your legs.
There are toilets every couple of blocks and you can pass through airtight doors to get to them.
You are parked pretty bumper to bumper, so you can't really walk around your car.
There are small windows on the carriages, so you can look out as you leave Folkestone.
When you get to France, the train goes round a huge loop to get to the platforms, so you don't need to rush back to your car as soon as you see daylight.
The actual tunnel lasts about 25 minutes, platform-to-platform is 35 minutes.
There is a bing-bong announcement when you're halfway through.
Stretch your legs, read a paper, have a chat and you're through in no time.
You go through passport control at the British side, so when you drive off the train in France you get straight into the motorway (unless that's all changed too!). Then it works in reverse coming back to the UK.
It really is a totally non-faff way of crossing to France.
Bon voyage!