Some things about Elaine's case that I find striking and/or may be worth revisiting is making sure they have spoken to every single person who registered as a guest at the RV park near where her car was found. What has stood out to me in reading about the serial murder/sex predator types is that they aren't noticeably creepy. They often blend in with others in the location and have a legitimate seeming purpose or occupation and shockingly sometimes even kids/spouse/girlfriend etc. Thus, if Elaine was a victim of foul play it was likely at the hands of an un-suspicious seeming person who had a plan and was potentially familiar with the area.
Malibu has a lot of wilderness which may be good temporary camouflage - but unless you are a survivalist or have a heli you are stuck with the PCH, its treachorous mountain crossroads and unpredictable traffic back ups/road conditions. There are only 4-5 niche hotels along the PCH plus Calamigos ranch, the RV park and campsites in the mountains. The PCH hotels are pricey and have limited capacity. They aren't great options if you want flexibility or privacy. The RV park, however, is a low key option geared towards self-sufficient types willing to forego turndown servicefor a nice view and proximity to trails. They have rental RVs and a cabin but most spaces are bring your own camper. The highway and ocean provide a good noise buffer vs the quiet canyons near Calamigos and camp sites. The RV park books up months during high season- but since people make their reservations so far in advance cancellations are frequent and can be scooped up at last minute as well.
I would also say that the vantage point up there overlooking the beach is rather optimal. That's why I would hope the Sheriffs department took the time to track down everyone staying there - even kids as they notice things adults don't. And to explore the unfortunately grim scenario that someone visiting the RV park (registered or drive by as its easy to access) maybe used that perch to prospect for a victim. eg Elaine pulls up and takes a doobie down to beach for a smoke and perhaps they hustle down and ask for a light and build a rapport. Not necessarily a registered RV park guest but someone who is familiar with it. Perhaps a younger looking person who seemed plausibly close to her age.
In any case, I have to think that those in the RV park had the best shot at seeing something. There's a seafood joint and a gas station right there too. There would be credit card receipts or video footage of lic plates at pumps that could add another promising list of witness hopefuls. Its unfortunate that the local papers in Malibu that circulate at the cafes locals visit regularly didn't put out a more alarmist and aggressive campaign to support the family. I cannot account for how myself and other locals missed this story at the time. Malibu is a small town and is blessed by many busybodies who trouble the city council with all sorts of nonsense that makes local headlines. I don't know if these sort of rambling hypotheses are useful at this point but if nothing else maybe my wild speculation or familiarity with area will trigger more concrete ideas that investigators can act on.
To Elaine's family and friends - there are many in Malibu like our family, who have not forgotten Elaine's story. We wish we could do more to help investigators connect the dots that we hope will bring her home to you.