I am 6'2", I have a 16-month-old and have him sitting on the passenger side. We drive 3 hours a day. I would be able to have him behind me, but I wouldn't be as comfortable. I also wouldn't be able to interact with him at stop lights, and hand him stuff.
I started out with an infant car seat with the carrier that locked in but we got into a car accident (with him in the car). After any accident, you have to replace the seat, so I went ahead and go the 3-in-1, so it will grow with him.
I know you are against it, but the carrier style makes it much easier to strap the baby in. You strap the baby in while the carrier is on the stroller, then all you have to do is move the carrier into the car base. If you go right to what I have now, you have to load them into the car and make sure you properly strap them in all while bending low and leaning into the car. My back hurts every day when I do this with my 16-month-old.
If I had the extra money to spend, I would have gotten a Y, so at least he would be higher up. My wife is on the shorter side, and drives an A4, we do have a 3rd vehicle, I have a full-sized Ram pickup truck. I can't drive that daily as the gas prices would actually pay for the Model 3. I may actually replace the A4 (it's a 2008) with a Y and give my wife the 3 just so I don't have to keep straining my back to load and unload him.
This is what I have now for my son:
Graco Milestone 3 in 1 Car Seat