I mean, I am talking about Highlander 2 versions, Endgame AND The Source - so I am sure there is not much distinction between those and a stroke victim- and I was posting from my phone.
Originally Highlander 2 the immortals were from the planet Zeist, and sent to Earth as a punishment / prison... where they gain immortality? but all of them are 'forced' by an innate call to kill each other etc.
The Renegade version, and or other cuts change "Zeist" to "The distant past" - retconning a retcon about them being aliens, I guess time travelers is better to keep within "the lore"
Both Endgame and The Source make big questionable changes to be "movie friendly" and "contained" to its own story, just in case someone going to go see Endgame didn't watch The Series, or someone watching The Source was not already a die hard Highlander fan. Each one makes new relations and characters when they could have used established ones for better consistency and emotional weight. They have glaring flaws that had no reason to be there, such as Sanctuary not being on holy ground in Endgame - just for an example.
And the part about the SUV in The Source was just funny, but it was fairly quick bit in a montage-y part near the end where I think it was Mythos just is like "Look! a brand new working BMW (i think) SUV! in the middle of nowhere (and in a post apocalyptic setting at that) yay!"