My wife and I will be taking a trip to south Texas in three weeks, and will be in a rental car which cannot be taken across the border. Other than walking over the bridge to Matamoros, can anyone tell us how we can get further down into Mexico on a day trip - or ever overnight to Moneterey. How about busses? Can we rent a car that allows us to cross the border, or even rent a car in Matamoros? Any help will be appreciated.