I have a 1998 A6 with 80k miles. I just changed the spark plugs and was surprised to find VW NGK plugs in it.
I put in Bosch Platinum Plus-4s, $5.99 per plug. Just driving around the block I could notice a major difference. It was not very difficult. Let me know if you want the steps listed out.

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Cleveland Rocks

You know I always thought I really liked Bosch plugs until I realized that the +4's I kept in my 99 2.8 were giving me consistently bad gas mileage. A swap back to NGKs brought the miles back to the mid-22's and I had power again! Your experience may vary, but that's my story!

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<em>Wayne</em>

Thanks for the info. So far everything seems to be running well and the gas milage on the dashboard display is normal, but I think it is good to track the actual gas milage.

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Cleveland Rocks