South Australia's highest court has upheld the Government's anti-hoon laws after they were deemed unconstitutional last year.

Under the state's Forfeiture Act, the cars of people charged with repeat driving offences can again be seized by police and either sold or crushed.

Last year, Chief Justice Chris Kourakis ruled that police powers to confiscate cars applied a double punishment to offenders, after an appeal by Port Pirie man Graeme Anthony Bell.

He was ordered by a magistrate to forfeit his ute after recording a third drink driving conviction in 10 years.

The Chief Justice's ruling was based on a similar legal principle to the failed 2008 anti-bikie legislation.

Within days of the decision, the Government said it would appeal.

The Solicitor General argued that while the anti-hoon legislation imposed a mandatory sentence, it did not undermine the independence of the courts because they would still decide whether a person was guilty or innocent.

The Full Court of the Supreme Court allowed the appeal and ordered the magistrate's orders be reinstated.

Police Minister Michael O'Brien has welcomed the judgement and says the Government will now considering when to recommence car-crushing.

He also says some of the cars seized by police are sold at auction with proceeds going to victims of crime.