My Car is Too Big For Me :P

So here's the story. In 2002 we decided to get a new car because the Maxima I had was old and starting to have issues but it was great and roomy. Anyhow, I start looking around and trying different cars but because of my size most cars were really uncomfortable, especially getting in and out of them, and I ended up turning to looking at SUVs because they are naturally bigger. So we ended up getting a Ford Explorer and it was comfortable for me to get in and out, etc. However, now it's too big! Here's the thing, when I'm driving and I switch lanes I slide around in the seat! Yes my seatbelt is on right and yes I tighten it up as much as I can to avoid this, but my butt keeps sliding (it's leather)! It's quite funny even while getting annoying. I need a smaller new car hunny! LOL