They have patched the original stragegy. An updated guide with some tips on how to do this post-update is below. The head-to-head bug has also been patched.
Thanks to all the players who offered additional info/tips/experiences etc for the old guide. If was fun while it lasted ;)
************ Map ******
I made a map cataloguing a number of start and end locations for the final showdown. It's colour coded and numbered to make it as accessible as possible for everyone.https://1drv.ms/u/s!AnF_pprqYcCrmYJccuPL_isMqAj7mgThese aren't all locations, they are all that I could remember.
Also to note, some aren't exact but still in the right general area.
If you know where orange ends let me know and if you encounter one that isn't on the map let me know (XBL screen of the final arena/circle and showdown end point) and I can update it.
In my experience these locations are set and do not have multiple end locations but I could be wrong. I even think head-to-heads have set end locations as well but are impossible to predict because of the many, many variables. I've had several head-to-heads ending in the exact same location.****** New Strategy ******This method can be stacked with the "Last Car Standing" achievement.
This can also be stacked with Pacifist but it is much harder to do now and requires a lot more luck. Many players have achieved this post update.NOTEs:
This achievement might still be a bit buggy post-update, if you completed the requirements and the achievement didn't unlock, try dashboarding and restarting Horizon 4, it's said that this will trigger the achievement to unlock.
Just a side note, when this mode ends up dying, you could probably jump into a game with a super low population and get it then. Might be a viable alternative in the future if you're having trouble with it. Or maybe they'll actually support it and make it fun with fun limited events where everyone has the same car only or everyone gets level 10 cars or something. Fingers crossed they support it and have fun things like that. (But hopefully they don't add anymore achievements amirite?)
------These are the steps/flow to the game that I take to get to the Final Showdown, the final race to determine the winner.
The Final Showdown
Tips for unbreakable objects
If you're successful you'll have gotten probably now the hardest, achievements in this DLC.Tips and experiences from other players
I'd recommend still reading the tips and experiences of other players in the old guide and comments. There are still some relevant info there and some of their experiences might give you the confidence you need to do it and/or might give you an idea of your own to win this thing.****** Old *Patched* Strategy ******
Let me know how you go. If you've any comments/adjustments/questions for this guide add it to the comments and I'll try and answer any questions you have.