Brake Disc Caliper problems of the 2005 Hyundai Sonata

I own a 2005 Hyundai Sonata. It seems that the brakes act funny (don't work right/longer stop time) whenever it is wet or cold out. I have had work done on it by the dealer and was informed that the front brakes were froze up and only half working. They wanted $45 to clean them for me. Instead I had my normal mechanic do the cleaning when he replaced my rear brake pads and rotors. He did the cleaning for free. About a month later on my way home, driving through the rain I came up to a stop light with 3 or 4 vehicles stopped at it, I pressed the brake with about fifty feet between my vehicle and theirs traveling at 45 mph and the car didn't slow down at all. I used my emergency brake to slow down but still hit a vehicle in front of me. No one was hurt. I can't say the same for my car. . . It hit an SUV. The SUV had minor damage but my car's front end was destroyed, and the airbags didn't deploy. The car was taken back to my mechanic for repairs and to have the brakes checked and the brakes were sticking a little but all he could figure out is that the calipers need more clearance. The brakes worked for him with no fixing but he also drove it in fair/sunny weather. To sum up the information I do regular maintenance on my vehicle. The brakes hardly, if at all work in cold and wet weather. And nothing is really being done even after I called the dealership about the issue. When I spoke to the mechanic at the dealership he said it was common for this car to have brakes freeze up due to rust buildup and offered to make an appointment to have them cleaned (once again for $45) there is also a part available for extra money of coarse that is a new caliper slide assembly with additional clearance. This tells me that Hyundai knows about the issue but is unwilling to do anything about it.