Are you specific on Mexican girls, or are Colombians OK? Escape in Wan Chai has a fresh staple of Colombians.
Sometimes the Colombians in there can be incredible, it's just hit or miss. A few years ago there was a Brazilian that looked like a true brazilian model. She one of the most beautiful women I'd ever seen, close to perfection. I turned her down after we flirted a bit and bought her a drink. I was wrapped under the finger of my GF who was more possessive then my SO, so declined. Damn it, still think about her sometimes.
The funny part is when I said no, she was pretty shocked, I don't think anyone has told her no before.
So if you need some Latin love in HK, escape is your best best.