Thanks ladies.
Chickielou, I don't think the car we're looking at is too much of a dunger - a 2003-2006 Nissan Wingroad station wagon. I'm leaning more towards they don't know enough about anchor points although DH did call them and they explained that the carseats they provide have tether straps but their station wagons ex Wlg don't have anchor points and they can't fit them in those cars. That's the bit I disagree with (since we've now found another rental place ex Wlg that does the same station wagon WITH anchor points).
Creative packing to get stuff into a camry would be fine but I'd hate to get there and find we just can't get everything in ..DH suggested I could sit between the boys in the back and we'd put the suitcases in the front seat. AHH NO THANKS!
Our other option is to bring our own car seats for both kids since ours don't have tether straps. But as I'm flying back solo with the boys I'd really rather not!
Anyhoo it looks like this other company (Go Rentals I think?) can put car seats in their station wagons so we should be set. Just going to cost us another couple of hundred bucks