DUI Checkpoints and the Fourth Amendment

The New York Times has a galling video report on the abuse of DUI checkpoints.  DUI checkpoints are not about catching drunk drivers.  Instead, the checkpoints are designed to steal cars from illegal immigrants.  Definitely check out this video.  Also, see this report.

In California, the police have a 30-day mandatory seizure of vehicles.  Yes, they'll keep your car for 30 days, even if you cure the defect that lead to the seizure.

For example: You were stopped driving on an expired license on 2/14/2010.  On 2/15/2010, you go to the DMV to renew your license.  You cannot get your vehicle for another 29 days, even though you now have a valid driver's license.

How can that be a reasonable seizure under the Fourth Amendment?  Assuming it's proper to seize your car when your license is expired (rather than allowing you to call a friend with a valid license to drive the car), how is the continual seizure of a vehicle constitutional?

Surely there's a pending Section 1983 lawsuit involving this issue.  Got any case cites?