I have an 04 G35 coupe and recently I have felt a slight vibration when driving that wasn't there before. I've had the spark plugs checked, replaced a bad wheel bearing and balanced all 4 wheels. The vibration is still there and I noticed tonight that when I hit my brakes there was an awful sound coming from the rear. When I got home, my left rear wheel was incredibly hot and the brake pad was so hot that it had changed colors (silver to bronze) Could it be that I have a warped rotor and that's what is causing the vibration?

Warped rotor/ seized caliper.

Thank you, I'm going to have it checked today.