BBM do you believe she was still alive at 8:00 AM whenn he showed up at work to establish alibi and then scuffled with her bettween by 11 when he showed body damage from a posible scurmish with her?
I work the time sequence backwards, in my thinking.
I start with thinking that the "end limit" for when he would have finished whatever he did with her and to her was before 10:15 am. By 11 at work, he has damage to his person and his car. And shortly before that, at 10:15, he's on video at the gas station, which to me is too close in time to 11 to think significant events happened between then and 11.
As for at what point before 10:15, we have:
1 he is making an attempted-alibi appearance at 8, but I don't know if we have witness observations either way as to the condition of him and his car at that point. All we know is that he came by, so he is awake and presumably dressed for work, and didn't stay for some compelling-to-him reason.
2 before that, we have him driving from the Shops area to his home from 5-5:30, generally
3 before that, we have him leaving the Shops with her in his car at 4ish and driving away and coming back before 4:45ish.
So that gives me two broad windows of time for him to get rid of her, one from about 5:30 to 8 (which also presumably has him changing for work and driving there) and the second from 8 to 10:15. And three windows of time in which he could have done something to her: from 3:45 to 5:30, from 5:30 to 8, or from 8 to 10:15.
I agree with JnRyan that daylight could have been a factor. But I think "gotta get rid of her" would have trumped that concern, if he wasnt done by 6:30 dawn or 7 sunrise. I can even see him taking her to hide, finds a place, gets started, hiding her, doing it quickly, and sun comes up and he's due at work - so he stops, runs home, tosses on work clothes, goes to work to try to make it look normal, then leaves and hurries back to finish the hiding process.
Or, maybe some other sequence. Just spitballing.
But other than knowing he got rid of her after he did whatever, I don't have anything that to me strongly limits the sequence of events further. I just figure all of it - whatever that entails - was done by 10:15, for the reasons I shared.