The driver would be arrested due to the drugs and possibly the weapons. They would be held as evidence. This hasn't changed.
Here's what has: Up until now, the driver could just be driving around with the money... no drugs, no weapons, no probable cause or reasonable suspicion, and the cops could seize it based on the extremely flimsy suspicion that the driver was a drug dealer. This money would wind up in the coffers of that local police department, to be used at their discretion.
The driver would theoretically have the chance to legally reclaim the money. However, the driver could easily wind up spending more money in legal costs than the original sum that was seized. And in some jurisdictions, the authority making the final decision in such a legal case is the same organization that seized the money in the first place.
See the issues here?