We've also got an '07 Odyssey with the SK Radian XT in the van. Ours are quite tight, I can't shake them around. We've got them rear facing as well -- in order for the seats to fit properly, we needed to reconfigure a bit -- we've got 3 seats in the middle row (2 rear facing one forward for our 3 yr old) and one in the back row (rear facing) -- the SRK are in the middle on the jump seat and on the passenger side with the passenger seat moved forward to accommodate the angle of the rear-facing seat(s). We attached the 2 in the middle row using the latch system along with the tethers - you shouldn't need the lap belt as well. The seat in the 3rd row in the drivers side - there's no latch so we used the belt - I recall it was tough to get this one tight but with a bit of elbow grease - it came good. Have you put the "wedge" on the bottom to support the rear-facing position? The other trick we use is to kneel in the seat while pulling on the latch straps...tricky but effective.

Good luck...we found them tricky to put in as well. Hang in there!

Janet
G - 12/07 35 weeks
GGG-04/10 30 weeks