Ok, this Dreamtime one is the one I saw people rave about. Quick search shows you should be able to get it around £140-ish, so double the price, and also big to roll. I think the smaller Thermarests are also very comfortable, but haven't used them myself.
Looks like you may opt for the dozer but just to say we have the Vango double - it is 7cm so proably the one you are looking at. It is as comfortable as our Fat Airics used to be and both DH and I (neither of us small) manage to sleep on it fine.
However, it is pretty mahoosive when rolled up. Although the Fat Airics (and presumably the Dozers) are pretty big, even two of them takes up less space than the Vango and, of course, you can put them in different places in the boot - they don't just sit there being enormous all by themselves like the Vango does. If space is no issue though, I can recommed it and it is nice having a double - I used to slide off the single Airic quite a lot - they are quite narrow.
hmm now even more confused. We don't have a massive car & always have a pram in the boot. I take it the vango double wouldn't fit on the floor in the back of the car? (both our kids are in car seats so they don't need leg space as such)
I have recently bought a Gelert adventure xl [I think thats what its called]. It is a 10 cm thick SI mat and is seriously comfortable I paid less than £40 for it so its quite a bit cheaper than the dozers.
Aargh! Just typed a message and when I posted it MN had gone offline for an upgrade and it all disappeared. Soooo annoying. Anyway, Migola - all rolled up, the Vango is a cylinder with a diameter of 34cm and a height of 63cm-ish - basically the width of one half of the mattress. We don't roll it that tight as we have lost the straps which came with it and I am a bit lazy about getting all the air out so you might be able to knock a few cms off the diameter. Maybe you could get it in the footwell of your car if your seats are quite far back.
thanks everyone, having thought about it I think I will get the dozers, because the DCs can use them when they're older if they go camping without us. They will also be better to store, and good for sleepovers. HOWEVER Ineedalife I'm going to check out the Gelert which seems dirt cheap
I have an XL Thermarest Basecamp (cost me about £70), and I found it very comfy (especially if you let it self inflate and then put a few puffs in it) I had it too soft the first couple of nights and woke with a bit of back ache, nice and comfy when it is inflated nice and firmly. I can dig out the link if you are interested in the website i bought it at that price.