I recommend a Taxi to and from. The cops are getting more crooked in both Acuna and PN now that a lot of the solders have left. They make up stories to pull you over and shake you down.
I know they did it to me last week. Said I did not stop at a sign and I know I did because I saw the cops so I purposely stopped and counted to 30 before I started again. Then They wanted to take me down town for a beer I had 5 hours earlier, said they saw me drinking. He originally wanted $2500 not to take me, then he dropped to $150, so I showed him I only had $60 and $5 for the bridge left. He made me give him the whole $65 and had to barrow money to cross back to the US.
During the day they are not as bad but I still have been shaken down for what they call Coke money of $10 or $20.