Of course, 2 year MOT's will prove their theory, that roadside testing was the right way to go.

Scenario:
Money conscious driver has the vehicle serviced and mot'd at the same time.
Now this is only required every 2 years, saving driver money.
18 months after mot, car falliing apart, suspension bushes hanging out, brakes to the metal etc
VOSA pull them over, another statistic added to the list.
Showing that VOSA were right to introduce roadside testing, as this driver would have got away with driving a dangerous vehicle if they weren't!!!!

However, if they'd left testing at 12months, then he wouldn't have been driving a dangerous vehicle in the first place.