The new info about the car being gone from their home 4-5 is an interesting new quirk. If it's known to be that tight of a timeline, seems more likely that that info may have come from somewhere near the premises. Three options come to mind: a neighbor who saw the car leave and return, a neighbor's surveillance camera that captured same, OR someone living at the home who has relayed that info.
But the only neighbor who came forward at the outset of things was the brisket guy, who said he heard/saw "nothing" - though he was outside with his smoker about 4:15 that morning. It'd be a bit odd if another neighbor just now stepped up with this exact car info after all the ongoing media attention (though anything's possible).
A neighbor's security cam might have picked up that car leaving the garage and returning, but then what are the odds that that Acura would've left at precisely 4 and returned at 5? (JMO, but this sounds more like a 'timeframe' to me.) The camera would've recorded the exact time, wouldn't it? Another issue with this is that, though there are exceptions, most people who have security cameras have them pointed at the various points of entry into their homes (front, side, and back doors and windows)--which position would not typically capture cars traveling down the street (at least ours would not). In this particular neighborhood, the driveways are in the back, with access along the back alley - there was no house behind WM's house with a driveway/garage camera. And we've been told that the next door neighbor immediately south (across the side alley--the home directly in front of 'the tree') had his home surveillance looked at (yard, shed, etc.) with no luck.
So to me, this seems more like a time frame given by someone who was at the house. But JMO and a hunch. The fact that WM has also admitted to being up at 3:00 am, doing laundry at 3:15 am, also seems to indicate he suspects someone in the house might know and mention that he was up, perhaps even heard the washing machine at that time...or else why would WM throw 'laundry at 3:15' into such an already unbelievable story? I believe he had to account for those particular noises and events happening, specifically, at that time...which is why he didn't say the simpler, "We woke up, the front door was open, and she was gone."