The more I think about Caspere's killer and that Cadillac, the fishier the killing gets. And the more it makes me think that the killer is not a professional. As such, I am doubting that the killing is related to the land deal.
A mint-condition, maroon, vintage, 30-year-old Cadillac Brougham with the D'Elegance package and whitewall tires would be one of the more distinct vehicles in Southern California. No professional would stakeout Caspere' Hollywood pad in something so memorable.
Further, he loaded Caspere's body in the daylight. When we did not know the location (episode one), this did not seem so odd. After seeing the neighborhood in episode two, loading during daylight seems reckless as Hell.
It struck me as odd during episode one that Caspere's body remained upright so well during the grand tour of Southern California. At the end of the episode, it seemed that Caspere's knees did not bend when the body was removed feom the car at the rest stop. I thought at the time that the killer must have propped the body in a sitting position until it rigor mortis set is, specifically so it could sit in the car and at the rest stop. This was confirmed in the autopsy discussion during episode two. But the atopsy also showed time of death "between 400am and 900am on the morning of the 26th." Rigor mortis sets in (at the latest) in six or seven hours, so the killer wasn't waiting for rigor mortis when he loaded the body fully 24 hous later.
Lastly (for now), taking Caspere the Corpse on a grand tour of Southern California was not remotely professional. Roll one stop sign or be unaware of one burned-out taillight, and you are busted while chauffering a dead body. Stupid and sloppy.