DS is still in his Regent with lots of room to grow. he's just over 40lbs and still on the second shoulder slots. with his Regent and DD's Decathlon there is no room for a third person in the back seat. this became painfully obvious a few days ago when we needed to pick someone up from the airport and i didn't have anyone to watch the kids. i'd like to pick up a HBB for him to use intermittently and possibly switch to when he does grow out of the Regent if needed. i haven't paid attention to car seats for about a year so i'm not sure what's on the market these days. the Nautilus is still on my radar but i'm not sure if it's small enough. can you recommend a good inexpensive HBB?