Thanks for the replies, chaps. I had done some driving abroad (Holland, Dubai, USA), but was still more than a bit daunted by the idea of 9 countries' various road layouts. Motorways were fine, but the more complicated urban junctions - where to look, priority, etc. But basically it's a very big car with UK number plates so the plan was that wherever there was confusion, take it slowly, indicate clearly and let everyone else avoid me.
Toughest parts of the drive were definitely the narrow country roads between Croatian villages and up/down the mountains. I only had to reverse perilously a few times to let tractors past (satnav route suggestions not always the best!). The LS400's Satnav gives up at Calais, so we relied on Google map printouts and the CoPilot app on the mobile (variable success, including some plain daft suggestions).
The Other Half had done all of the hotel planning, and then after that it was 'make it up as we went along'. So at a vineyard, we did the tasting (or rather the OH did!) and then we asked for suggestions for local cheese makers, then set off for the next village with a name and just a rough idea of where to go. One goat cheese place we only found because I just noticed a goat skull next to the gate. Foodwise, the find of the trip was that local salami - so tender and juicy and far tastier than the supermarket/deli stuff over here.
Graham, I'd definitely join in the 'just do it' chorus. I've never done this before, and it was fun - a completely different sort of holiday. Tiring at times (a 4hr autobahn trip in pouring rain on Friday took over 8hrs), but at least we got out feeling fine. Had the LS seats' lumbar support thingy fully set forward which really helped.
Why only 2600 miles? Just happened to be the result of the route we planned, with a lot of quite local trips, from the 6 places we stayed at. We went for quality, not quantity! ;)
Only prep I did was a belt change (car was new to me and there was no evidence of a belt change) and two new front tyres. I'll check the brakes, because in a few of the longer downhill stretches, there was definitely some fade. Never lifted the bonnet once, just frequent visits to the petrol stations. Although the last leg of the trip including the tunnel and Kent was pretty efficient, as you can see:
One negative: the LS400 boot is not as big as I first thought. With two small suitcases, we only had room for about 70 bottles. So we're already planning a trip to Riesling country in May...