Yeah, mine wasn't too bad either (tight harness, chest clip generally in the correct area) but I did FF him way too soon. He RF until 15m when he had surgery on his hips and he wouldn't fit in his Snugride in the spica cast. We had assumed the hospital was going to rent us a spica carseat but they told us to lay him across the back seat and put the seatbelt around him.
DP and I didn't know what else to do so we got a cheap combo seat that didn't really have any sides. I was really upset because he was only about 18-19lbs so I didn't want to FF him but the hospital staff kept telling us "well he'll be 20lbs with the cast on".
I was terrified the whole way home and we didn't go ANYWHERE else but the hospital for cast change and then removal. After he was out of the cast, he was right at 20lbs, so I thought he'd be okay to stay FF. Later I learned a bit about how it was safer to keep RF past 1 and 20 so I attempted to install the COMBO seat RF.
Obviously I couldn't figure it out so I just kind of let it go. Then when he was 2.5 I started reading more about it and then I saw the video about Joel. So I posted a thread on MDC to try to get some help turning his seat and that's when I figured out I had a harness to booster seat, not a convertible AND the minimum on our seat was 22lbs/34in and DS was not even 21lbs and 31in tall. So, even though I was incredibly broke because DP and I had just separated at the time, I went out and bought a Scenera.
Oh, and lets not forget the time DP installed the combo seat with all 3 seatbelts (his reasoning since we didn't have a top tether anchor) and the time I put a locking clip on a lap belt, and the RF tether on the Scenera.