[Q] Can't skip/replay tracks from car stereo over bluetooth topic

Hey all, Just recently replaced my Galaxy S3 with the Z3. I love it so far except for one annoyance. The phone connects to the stock radio in my car over bluetooth (2010 Mazda3) and plays, except I can't skip or replay tracks as I want from the car stereo head unit. It will just play the songs from my library on the phone. I can however do it from the phone itself. The only control I have from the head/steering controls is volume. My old Galaxy S2 & S3 worked flawlessly in this respect, why am I having trouble with a brand new phone in 2015? Any suggestions welcome.
Thanks.