Labour's campaign bus is officially called Big Red.
But this week a more appropriate moniker was surely the David Cunliffe Blunder Bus.
The signs were never really that good for the bus from the campaign's first week, when it had a prang in Tauranga, escaping with scratched paint.
This week it was Labour's campaign itself that veered seriously off-course when leader Cunliffe botched and bungled his way through a defence of Labour's capital gains tax policy.
This put a serious dent in Labour's campaign. It could turn out to be a tragedy for Labour.
The election was there for the taking and suddenly John Key has snatched it back.
Dirty Politics was just what Labour needed - it was like someone hit the reset button.
Finally, Key and National were pulled down a peg or two.
Cunliffe's past sins looked like they were forgotten. Key was suddenly the sinner.
The poll gap was narrowing and the MMP mathematics made a Labour-Green-NZ First combo possible.
Cunliffe clearly won the first leaders' debate. Things were looking up. Then came Key's pre-meditated hit on the capital gains tax at the Christchurch debate.
I had a front-row seat for Show Me The Money II as Cunliffe was left flummoxed and reeling.
He froze in what may be the most crucial moment of his political career.
It could and should have been so different. Key had his facts wrong about Labour's tax applying to homes in family trusts.
Cunliffe should have known this answer - and hit back on the spot with "John - you are wrong, you are misleading New Zealanders".
If Cunliffe had done that, the script for Show Me the Money II would have been a desperate Key out to smear Cunliffe.
It could have been spectacular - an assured Labour leader outwitting Key where Phil Goff had failed.
It would have swung the debate Cunliffe's way giving him a 2-O lead in the debates.
Imagine the narrative - "Cunliffe puts flailing Key on the back foot".
Instead, it is now a "what might have been" moment for Cunliffe, because Cunliffe somehow made it even worse when he stuffed up explaining the inheritance aspect of the capital gains tax - again, that's something he should have known.
You don't give Key two chances.
Key was suddenly back in control.
And the Cunliffe blunder narrative was back.
The road map always looked like it was going this way - the botched baby bonus, the secret trusts, Herne Bay house, Donghua Liu and that apology for being a man.
Cunliffe has shown he is better than this.
He has two weeks. The TV3 leaders' debate on Wednesday will be crucial.
Cunliffe needs to get off the Blunder Bus. Cunliffe needs to get some control back.
And he needs to hope that moment he went missing in Christchurch doesn't turn out to be Gone in Sixty Seconds.
Winner of the week: John Key. The mud from Dirty Politics isn't sticking and he got on top of Cunliffe.
Loser of the week: David Cunliffe. Lost his way and lost touch with Key's lead.