I agree Witness 28. My primary theory, as previously posted, relates to revenge via extortion.
IMO, Inland Motor Repair proprietors Michael and Samantha may have been asked to do some illegal automotive work.
IMO Michael and Samantha knocked back the request.
IMO, given that the request would have been made by a person or persons likely involved in organised crime, this definitely would not have been well-received - (not used to knockbacks). Additionally, Michael and Samantha are now aware that that person is a criminal, and may mention it to police.
This scenario may tally with daughter Jess' comment at the press conference regarding her mother - "Mum's a really strong woman and she's far too strong to give up this fight."
IMO the knockback may have resulted in Samantha being abducted for extortion purposes (which may have gone awry) eg Samantha putting up a better than expected fight, or as pure revenge - a message to Michael - who's next?.
My secondary theory is that IMO Samantha may have been involved with someone (Samantha spent Christmas and the annual coastal holiday away from her family. I am aware that she was suffering from Covid, but at that time during the pandemic, isolation period was only five days. IMO it seems a bit odd not spending any time with her kids). I am wondering whether anyone she knew lived at/near Mt Clear.
All just speculation - MOO