The last two presets cause the antenna to change height. Not much, just a couple Inches. Is this normal?

 

mines does this too..

 

Yes, it's supposed to adjust in accordance to the wavelength of each radio frequency. I'm pretty sure it attempts to adjust to half of the wavelength for best reception. For example 101.1 Mhz wavelength is approx 2.96 meters, so at that frequency the antenna should be 1.48 meters tall or as close to it as possible. That is also why on AM the antenna is fully extended. Probably not a necessary feature but I suppose it helps.

Anyways, it is normal.

 

If anyone out there needs more confirmation on this...Then yeah, Mine does this too.

 

Mine used to do this when I had my factory stereo.