RA tether questions

I have installed the RA rear facing in the center backseat of my Honda CRV. There are three tether anchors in the rear of the vehicle, which would be behind the carseat. Should I use one of these or should I tether it to one of the front seat tracks bolted to the floor? I also haven't quite figured out how to use the tether strap quite yet. Apparently, the directions aren't idiot proof. Any help would be appreciated. Another thing is, I have the seat reclined all the way, but the angle of my center backseat makes the carseat almost a 90 degree angle. Is it ok to place a noodle under the carseat to recline it more?
Thanks for any help!
Gretchen and Lyra (12-30-02)

[Momof3Labs]

This should help with the tether question:

http://www.angelfire.com/wa3/isakswings/ratetherrf.html

And we used a noodle or rolled up towel with our Roundabout to get a better angle when Colin was younger, but we don't use it anymore. He'd rather be a bit more upright now.