I've got all the vehicles including Yoshitsuna and Super Robo Suit. The only one I'm missing is FX7 Skydiver. Has anyone had luck getting it to drop in 3-5 like the other thread suggests? I tried farming for it on the last two stages of the Petta version for a few hours but haven't seen it pop yet.

This are my Bonus List results for the Demonic Elite Four stage:
Drill G (6m)
Drill G (10m)
Sonic Blaster (13m)
Dark Gear XX (14m)
Sonic Blaster (15m)
TX5 Hopster (16m)
Dark Gear XX (18m)
Dark Runner Z2 (20m)

It may be a one off, but it seems like vehicle drops became more common the longer I farmed. Only two showed up in the first 10 minutes and then 6 in the next 10.