Today I just purchased a 2008 RDX. I drove an Integra for 17 years and finally put her to rest. Now, I love this new RDX, but in order to maintain my budget I purchased one without the navigation package. I'll live, however, I was wondering if in the future, I could retrofit to a navigation system. Does anyone know if this is possible? I felt silly asking the guy that I just bought the car from...