Car buyers chasing popular scrappage models could miss out because the scheme is running out of cash and ending in chaos.
Limited funds remain for the second 'exit phase' of the scheme, in which quotas are allocated to manufacturers according to how popular their cars have been during the incentive allowing it to come to a smooth conclusion by the March cut-off date.
Scrappage conclusion hits confusion
However, the Department for Business Innovation and Skills (BIS), which administers the scheme, can't release each manufacturer's quotas because the figure is continually changing.
Some manufacturers have been reporting orders every few months not fortnightly as required while one has recently cancelled 3000 orders in one go.
The number of available scrappage 'vouchers' rises and falls as orders are cancelled and confirmed.
The scheme's administrators know how much money is left in the scrappage pot, but it's difficult for them to know where the cash will be allocated.
Government won't name and shame
A spokesman for BIS would not name the car makers that haven't complied with the rules, but said: 'There are a number of manufacturers that didn't put the amount of resource in that was necessary to manage it.
'Many vehicle manufacturers put their orders through in batches every two or three months. Many were taking orders and then cancelling them.'
The end of the scrappage scheme doesn't mean the end of big savings, however. Look through our deals section and you'll see that you can get save thousands of pounds on hundreds of models.
You may also still be able to convert your old banger into more than it's worth because some manufacturers will continue scrappage-style programmes. Kia is the latest to do so with its 'seven-year switch' that's available to cars between seven and 10 years old.