Who said I was talking about YOU???
Chill. If you've been taking you lo to well baby checks and vaccinations, they are supposed to be doing patient education and providing hand outs explaining this to you. The current handouts are outdated, but they all say 1 year and 22lbs (if lo hits 22lbs before one year, you have to get a seat with a higher rf limit). The nurses have been instructed to pass on the new canadian pediatric society info of a bare minimum of age two. If they have not done this at your six month check, they are not doing there job.
If you have not been taking lo to get vaccinations, you would not have got these, doctors/pedis don't give that info out here. That's public health's realm. The link dhviel posted is current. If you need help choosing a seat, wander over to the Gear board, we'll sort you out and if you need, find you a tech in your area.
And at some point lo will be fine and learn to cope with sitting alone in the back seat. I'm sure your dh would like to have your company in the front seat.