From what I read most first offenses are pled down. Not to mention the cops had better hope they did everything exactly right and had probable cause to search or the prosecution won't be able to submit the gun as evidence, in which case it will be dismissed with no evidence. Even in California, if the barrel was sticking out of a bag, they have to show they knew it was an illegal gun vs a legal one to have probable cause for a search since it was a routine traffic stop.