HR and SG, can't focus attention and innuendo on people who aren't supposed to be sleuthed, and that can at times get posts removed. But moving on, if we know EA didn't have to worry about his parents, looks like that answers my question of how he could have gone home and cleaned up right before or after the gas station stop, before going to work.
So that puts us here:
EA's said pointedly it couldn't be him because he didn't have time to do anything with CM, because he was at work at 8, which was a lie of course, which makes me believe that the "when he should have been at work" time period (the window from 7:30-ish when he would usually leave home, to before getting gas at 10:15) that he wants to obscure is the place to focus on him doing something with CM.
So now I'm guessing we have:
1 he goes home about 5:30 and wakes brother for an alibi that he went home
...by the way, doesn't this 'wake the brother' thing come off as purely intended by EA to create an alibi? why else would you come home and rouse a sleeping brother? sheesh ...I have every belief that the brother was woken, and probably puzzled why he got woken up.
2 EA goes to sleep, sets the alarm as usual
3 wakes up as usual and gets ready for work as usual
4 leaves the house at 7:30-ish as usual
...probably dressed like he's going to work?
5 but he does NOT go to work, and here begins the 7:30ish to 10ish window when he drove somewhere, with CM in his trunk, and got her out of his trunk
...let's guess he took an extra shirt and some shorts to get dirty
...this 7:30-10 would be the time frame (daylight, weather, driving radius possible) etc to examine imo
6 allowing for the widest window possible, that 2.5ish hours probably also includes some sort of car wash, most likely got a stack of quarters and went to a self-service where he could vacuum it himself as well as clean exterior
7 that leaves us the following events in that window:
a - drive to wherever, up to 1 hr*
b - put on other clothes, get CM out of the car and hidden, up to 20 mins
c - drive back, and also stop somewhere along the way, to wash the car, up to 1:20
...I'd figure the car wash would have been done at earliest opportunity, just because, but can fit anywhere on the way back
8 at 10:15 he's getting gas and cleaning a couple spots he missed
9 with a full tank, he's around the corner to his house by 10:20 or so, takes a quick shower and puts his work clothes back on* ....his parents are gone, not there to notice his return, maybe brother already has things planned and is gone too
10 he leaves the house at 10:40 or so, and is at work at 11 or so
We have to keep in mind that each of those actions took however long it took - it's not like EA was on a stopwatch having to fit everything in as noted and by 11, but rather that we know it ended at 11ish so we only have to have a rough idea that each of those sets of events could all fit in.
Is there anything that doesn't work?
* - if he had his work uniform on in the gas station video, we narrow the "drive, remove/hide CM, and return" window by another 15-20 minutes, as the shower and change of clothes seems to happen before 10:15 rather than after ...in that case maybe we're down to a 50 minute time limit for the drive each way, plus 20 minutes for the stop and get rid of CM, plus clean the car for 20 minutes, plus back to the house to clean himself for another 20, and getting gas at 10:15.
ETA - I have found out that QF didn't have any actual knowledge of whether EA's parents were home or not. What he had said: "I thought I read/heard somewhere that it was only EA and CA home that weekend and that their parents were out of town. Again, I don't have a link, just thought that was known information from EA's and/or CA's discussions with investigators." And later he again asked: "Haven't we also established that both were out of town that weekend? Given that it was a holiday weekend, it's likely that they didn't come home until late Sunday or, perhaps, even Monday, the actual Labor Day holiday." Then later he posts simply using the assertion/assumption that they were out of town without any validation. So no actual info, and we still need information or verification that EA wouldn't have bumped into his parents, if he had returned to clean up either before or after 10:15 gas stop.