Buckle Up?

I have a three year old son. If you have children, you understand just how curious they are at this age, additionally they pick up on things easily and like to try out their new-found skills/language immediately and frequently. This being said, I have a problem.

When we hop in the car, we buckle our little man into his Graco car seat with the 5-point (recognized as the "most safe") harness. This involves two straps buckled between the legs and a plastic thing snapped on his chest. About a week ago, as we were hopping out of the car at home he stopped me as I tried to unbuckle said plastic chest piece. "I do it Mommy." I figured, why not let him try...and try he did. Not only did he try, but he succeeded. "Great," I thought, "now he can free himself." I wasn't too worried, I assumed he knew that we only took it off when we were getting out of the car.

Fast forward a few days.

It's about 6:45 a.m., I am sipping my coffee and driving to the Day Care, little man safely strapped in in the back seat, or so I thought. At the stoplight just before his daycare, I felt a tap on my arm. "Hi Mommy." I spun around, there he was, leaning as far forward as he could, no shoulder straps on. I flipped on my hazards and jumped out. The part that goes between his legs was still securely in place, but the chest harnass was open. I strapped him back in, and drove into the day care parking lot and told him to do it again.

It took him about 5 minutes, but he did. He pushed down on the top button of the chest harness for about a minute and wiggled it out. From there he just pulled at it until the bottom one came loose. Then he was able to slip his arms free from the shoulder straps. How I didn't notice this as I was driving, I'll never know. But he was so quiet about it, as if he knew he couldn't be caught. (After he got out the second time, I made it clear to him that this was NOT OK and NOT SAFE and to NEVER DO THAT AGAIN. But you know kids, they don't tend to listen.

I think part of the problem is the amount of room he has in the back seat of my vehicle. It's an SUV, he's right behind the driver and I have the seat pretty far forward. Far enough so that he can't kick me if he tries. He doesn't have that kind of room in Dad's car. I also can't quite see him in the rear view mirror, unless I stretch a little, so it's not like I could see what he was doing.

When I pick him up tonight, I will tighten the harness one or two times tighter then I think it comfortably should be - and hopefully with a little less room to move he will be unable to free himself from his safety belts. If not, I don't know what to do.

A car seat is supposed to be safe. Supposed to keep them strapped in and should be (in my opinion) "child proof." The child locks are on on both back doors, in case this situation arises again.

I am also hoping that as soon as he's in his winter jacket he'll be bulky enough that he won't be able to wiggle his way out. But once the shoulder straps come off, he's pretty much free.

Have your kids ever learned to do something that affected their safety? Please share!