1998 Audi A8 Oil Burning

I recently purchased a this vehicle from an auction house. When leaving the dealership i noticed a smell like rubber burning and realized it was oil burning. I took it back to the dealership and they put the car on the lift and we noticed oil on the catalytic converter...that was the smell. The car was sitting for quite a while, I recd the carfax report and the car was maintained regularly through the Audi dealership. I would like to have a mechanic check the car over, where can I find such a person and do they need to be a certified Audi mechanic to simply check the car through?

Suggestions?