Why would that make sense - to bring her car to her body? A body in that landscape is far harder to find visually, in your day to day business, than an unobscured Hilux. It's a bit like putting a giant arrow pointing to her body. We don't yet know what state her body was found in, and an estimated time of death. It seems the Hilux has been there no more than about 12 days, assuming someone has been in that part of the property then and the car wasn't there. Maybe she has been there all along, or maybe they were both dumped there (if foul play) just recently. The best case scenario is that it was a tragic accidental/natural death, and she got disoriented, had a medical episode, a bad trip etc and had been wandering around until she died, or driving around (far less likely) and left the car there recently.
I'm not buying that though. My money is on foul play, but why? Possible reasons are endless: she knew too much about a situation, she had the power to get someone into trouble, she was causing "trouble" for someone (I'm thinking along the lines of her recent court appearances), there was a drug deal gone wrong, she was in with a dangerous crowd, she did something illegal/immoral/just something that pissed someone off, an argument broke out and someone got physical, she was accidently hit and killed on the side of the road and it was covered up, she picked up a hitch hiker and it all went downhill, I could go on. Feel free to throw out your theories.
Hopefully as details come to light, things start to actually make sense, for her family and some form of closure. I think there may be elements that never get expanded on though, so we -the public- may never find out the whole situation.