Funny you should say that because my gut feeling from the start was that he killed his victims in his car. I'm not sure why I had that gut feeling, and it sure wasn't based on anything solid, it was always just how I saw it in my mind. You know what I mean, I'm sure. But anyway, I still have nothing to base that gut feeling and I have no clue where he killed these poor women, but if you think about it, killing them in the car does make sense given the isolated area of where the victims were found. Pull off Ocean Parkway or around the Jones Beach area ( didn't RH work at Jones Beach Park at one point ?) , and who would be the wiser. No nosy neighbors to see, no one to hear, not far to drive to a dumpsite, etc. etc.
Just random thoughts prompted by insomnia, I guess.
ETA: Wanted to briefly mention how much I have valued your input on this case over the many LONG LONG years, Fredna. I could say the same of so many members who have tirelessly research this case for years, but tonight I'm singling you out. So thar !