I checked it mostly with 2 tile vehicles. With those, it was certainly an improvement over the old one.
Then I had to fix something and I guess I broke that specific edge case where you go diagonally while holding a 1 tile vehicle diagonally to you.
The placement is supposed to work like this:
(Try to) Move vehicle in the direction player goes
This rotates the vehicle
If the vehicle is no longer adjacent to the player, (try to) move it so that the held point is where it was in relation to player
That last point should not happen when the vehicle stays adjacent after first move, but for some reason it does.