These folks are friendly and knowledgeable. I had a bad sulfur smell coming from engine area of my used RV. (after only having bought it 2 weeks earlier!) Interstate had me pull into the garage and diagnosed the problem immediately. The coach battery was getting fried and I learned it was the wrong type of battery! Interstate knew exactly what I needed (AGM Deep Cycle). They also checked the chassis battery to make sure it was good. Now that I've found them, I plan to bring my RV here annually to have the batteries checked.
p.s. the dealer I bought the RV from reimbursed me in full for the battery.