Police is quite active recently, lots of road block in my area which I feel quite safe

I was in a ger's house n on my way back home at 3.30 am n was stopped by a group of police, a big group about 10.
A policeman came, spoke Thai, which I responded I didn't understand. He was smart, signaled to another whom can speak English. He kept telling me to pay 500THB which I refused and asked why a few times. Wasted some time before he told me, my car plate was missing.
Too bad, I went straight to my car and took out my police report and immediately he let me go.
If only, he told me, I was drinking... then I LL, give him some money

I was drinking a lot with some samsters but luckily, I spent abt an hour plus in my ger's house. The smell of beer has been covered by shampoo, soap n ger's body smell.