I just purchased a used 2004 GX470 and got 45000 mile service done by Park Place Lexus in Grapevine. I was impressed with their service but it was pretty costly. I was wondering if forum members can give some advice on the following:

Are Toyota dealers a better choice than Lexus (prices maybe lower and quality is good??)?
What about taking it to a regular auto shop? Any recommendations for auto shops in North Arlington, Texas area?

I also purchased Prism extended warranty for additional 4 years (or 100,000 miles). Does anyone know if this is a good warranty company?

I don't know if your warranty company is a good one. I purchased the extended warranties for my wife's 2002 Mercedes ML320 and for my 2004 GX470 from Carmax and am pleased with them so far. We had to use the warranty on my wife's car for a sensor under the brake pedal. We took it over to Carmax and they wouldn't touch the issue because they originally thought it was a transmission issue. Carmax then called the local Mercedes service shop, had it towed over there, offered a rental car (We didn't use it becuase we were going out of town the next morning), and the car was done by the end of the day. We originally thought it was going to take two or three days with the car having to go to the Mercedes dealership, but were pleasantly surprised with the results. And all that for $50. Not bad...