I've got a minibus on standby or do we load up several vehicles again?? However I have a
Porsche Boxster 3.2S at the moment....tempted to take it!!!
Take the Porker without a doubt, driving down there I'd expect you to have the most fun in it possible with your clothes on!!

I'm surprised you're even asking this, Actually don't take it it's rubbish it'll cost you loads in fuel, but do let me know if there is an unused Boxster in June I may have a use for it??

Which ferry route do we take??
If you're in convoy in cars (especially with your choice) I'd go Dover->Calais, it's not a short drive but a fun one, stay off the main arterial roads for more excitement. Get a cheap Speedferries booking while you can.
Which days do we travel??
Depends on how much holiday people can take & how long the woman lets you go. I'd call Thursday the latest for departure, at least you'll get to see some qualifying, Wednesday is a bonus.
Where shall we park in Houx Annexe?? (hopefully got tickets)
Well there is a large CA related contingent at the far left of the campsite (nearest Houx), Steve Brown & BobU we plan on being around there next year.
Do we hire a beer cooler & tap or take a chest freezer??
No idea what's best, I'm still a little inexperienced...unfortunately we drank hideously uncool beer this year

But I'm sure someone else will soon be along with some stirling advice!!