I just received my new Frontier 85 and intend to attempt a installation tomorrow - yes, I am intimidated! I intend to attempt to install using a lap belt - my child is over 40 lbs - with the harness. I am amazed at how heavy this seat is!!! I intend to use this seat for many years to come and expect to one day use it in booster mode (without the harness). My 4 year old has already complained - "Mom, this is a car seat - not a booster seat! It has the same straps!" Is it really ok to use without LATCH in booster mode? When I look at the video on the Britax site they only show installing in booster mode WITH LATCH (which would exceed my vehicles limit). Am I the only one concerned with the weight of the seat and that the seat belt would be holding my child AND the seat in a accident???? Is this really going to be my last seat????? Should I have kept her in her Boulevard a few more years then bought a less expensive lighter booster seat without the harness???