I am looking for a hotel in Mexicali. I fully intend to monger when I go but have little interest in "going upstairs" in the clubs or hit the mats in the massage parlors. I want to bring a senorita back to my room. The problem is that I want a good room... the best I can buy but from what I read here the higher the rating the less likely they will be to allow visitors of this kind. So...

Which are the best hotels that allow chica visits? all nighters too. Or at the very least which of the nicer hotels are easiest to smuggle in a young thing?

Hi Camper
for a zero hassle hotel that is decent try Siesta hotel.
I wrote about it in the hotel section

The best hotels I've used so far are Hotel Araiza and Hotel Calafia (both owned by same company). A Jr. Suite at Araiza ($115) is pretty nice, with a separate living room, though there are renovations going on there now and even a third floor room was a little noisy. A Jr. Suite at Calafia ($82) is a larger room than normal, but not as nice as Araiza, though cheaper and definitely do-able.

Either way, when you register, tell them you want a room for two persons (your wife is the second person), and you want your wife's name on the room too. Have a name ready (I use the name of whatever current novia I have, or a previous novia). You will now have a room for two people, and if you have a car (ideally), you'll have a pass for your dashboard or rear-view mirror that shows you have a room for two people. After that, coming and going for me has never been a problem.