"My worry was two-fold, the one you mentioned, that in an accident she'd be more exposed and that she'd also be in full sun. That one is easier to tackle with a sun shade, obviously."

"Yeah I always use the base. What is the problem with the extra height? I don't think aerodynamics factor much ;-) It's easier to take the kid in and out with it a little higher. I always put the seat handle up and joke that it is a roll bar. But anytime I've crashed a long john (mostly in the snow) it slide on the side and doesn't seem to want to roll."

"thanks for the tip. i am trying to decide what's the most successful route to pursue. i'd like to get away without using the base since it will raise the top of the seat over the height of the box sides."

"You must make a lap seatbelt like in a car. The best way I do for my cargo bikes (bicyclefamily.ca) I build is with a footman loop (google the Faucher website for it) anchored to the floor. Drill through and use minimum m5 bolts and wide washer. Then any webbing or belt that is solid will do - old car belt if you can find one. (strapworks is a good internet source for webbing/buckles). I could post photos one day I guess. Cheers, rusl"

"Do you have a tutorial on mounting the infant seat in the box? Do you drill to mount the base or just anchor in tie down belts to go beneath the seat?"