Last week I went to Chetumal for weekend shipping, while I am on my way to American plaza from Mexico border, I was driving extremely slow (under 40km), trust me I am slowest driver on the highway, cause I heard ppl say Mexico police are very corruption, when I pass by the police truck which was parking on the roadside, I saw they start follow me and put horn to ask me to pull roadside, then the police came out and told me that he saw me driving over 40km so he will give me a ticket or I could pay him 300 pesos for bribe! although I don't speak good Spanish but I point out some Vehicles even fast than 40km, then he told me he only saw me drive over 40km, I was asked him if there is any proof he can shows me, then he says he saw it, that's all!(what a ridiculous), however, I don't want to argue w/ him, I paid him and had bad trip for that day in Chetumal, after I came back from Chetumal, I asked my friends whom ever have same problem like me, there are over 70% ppl have same experience..... I am wonder how many of you also have driving problem with Belize License plate in Chetumal?! However, I feel now Chetmail is not good place for weekend shopping anymore.

I know they do like to sit there on the side of the road after you pass the fumigation station, and I have seen many cars (Belize and Mexican) pulled over there. That day was not your lucky day, they were probably trying to get enough money together to go to Burger King. I lived in Chetumal for 2 years, had my Belize car with me the whole time, with Mexican car insurance I bought online from sanborn's. I drive slow, Mexican cars pass me all the time beeping, but was never pulled over. I had a little run in that was totally my fault (he wrong way on a one way street), and I cried my way out of the ticket. My Spanish is bad too. You should have argued with him even if its in English and they would have given up and let you go with a warning, because ultimately you are a mark and if they waste too much time on you, then they can't get to Burger King right away and have to find another mark. My husband was pulled over once with me in the car and talked his way out of a ticket, showing them his wallet, "see there is no money."
You could drive up to the Belize border and cross in a taxi and taxi it from there, or you could try it again and if they stop you, tell them no tenga mordita, argue with them in English, tell them you have no money. If they really want to write you a ticket, then they will do it and you won't have to pay them off. Take down their vehicle number. Do not be afraid of the Mexican police, that is what they want.
You could also complain to the Mexican consulate in Belmopan telling them that the police near the border are harassing Belizean drivers for bribes, and they will take that serious.
I had a problem with my visa once in leaving Mexico to go to Belize to photograph a wedding, the immigration officer wanted to take away my visa which still had time left on it. He wanted his bribe. I pulled a COPY of my visa out of my purse and told him that if he took my visa away I was going to Belmopan to the Mexican embassy to complain about him. That was enough warning for him to give me back my visa.

All I Concerning about the police power, do you know in Mexico's law system just like China, if police "accuse" you something illegal, they have right to put you in jail, unless you can provide some evidence to proof your innocent. so i won't ruining my trip like that.

I live in Belize City, so I don't think it's good idea for just complaining, I also doubt the the Mexican consulate will listen your complain for 300 pesos...

Some of my Friend told me if they want give you ticket, just take it, cause they haven't way to force you to pay since you aren't citicen.

I also heard my firend says sometime police ask your certificate for your car, if you can't provide it then they want bribe, but actually there isn't any certificate for that, well~ I just feel Mexico police just like begger for their side job, aren't them?!