I'm looking for a way to fast forward "in chunks" as well. For example, I also listen to hour-long podcasts and if I ever change tracks and want to return to the previous spot in the podcast, I have to hold down the > button on the head unit. Holding down the >> on the steering wheel controls doesn't work (it just skips to the next track). Would be nice to be able to skip a minute or two at a time.
But as far as it going to the beginning of the podcast/track when you start up your car again - this doesn't happen to me. I use a phone with a microSD card, and I usually plug my phone into the USB cable before starting my truck. It will continue playing where I left off.