Have not found "adaptive cruise control" 7" of owners manual is rather daunting. LOL
OK this isn't easy to describe but I'll give it a shot. On the right side of the steering wheel there are 4 'outside' buttons'...
1. Top left--a pages/book looking symbol that runs you through all the menus.
2. Top right---cruise button. Turns cruise control off/on.
3. Bottom right--cancel....hopefully obvious.
4. Bottom left--automatic cruise control. Looks like a car and a lane sorta on the symbol.
There are two 'toggle' type switches/buttons on the 'inside' of this array.
1. Right one. Sets and/or adjusts up/down the mph for cruise.
2. Left one. Has the word 'ok' on it. This button has an up toggle, down toggle, or press it in for 'ok'...this is the button that is in general the reset button for stuff.
To get auto-cruise on and set distance.
1. Turn on cruise.
2. Set speed like normal.
3. Pre the bottom left button (item 4 above). I think you need to hold it in 2 seconds and it turns the auto cruise on. hold it in 2 seconds to shut off. Once it's 'on' then press and release toggles distance. 82, 106, 130, and 172 ft. press once it moves one, press again, and so on. You will see the cruise symbol on the dash get 'bars' on it as 1,2,3, and 4 bars which represent following distance. My personal preference is 1 bar.
SEPARATE FROM THIS: There is also a setting to change how quickly the auto-cruise reacts to changes in the vehicle in front of you. If you have a long distance set but sensitivity high you are going to be in for a whole bunch of unnecessary speed changes. Setting it to slow makes the car react slower which reduces unnecessary changes but obviously if you are following close is less than ideal. By default it is on 'medium. I find 1 bar of distance and 'medium' reaction time to be pretty good. This sensitivity setting is down in the bowels of the menu system if you are interested...not in the cruise buttons.