Issues with a new to me Audi Q5

I purchased a 2009 Q5 w/ 90k miles on it last week. When I bought it there
according the computer the oil level was about half way. Over the course of
36 hours the engine leaked an oil like substance that had a fuel smell to it in
multiple places that I parked, and the second morning I had the car the
computer said there was no oil.
The deal towed the car back to their shop to have the issue fixed. They
called me yesterday and claim the issue was just a purge valve, and that
they would take care of it.
From what I have been able to read online and the shops I have talked to,
these issues do not add up to what the dealer is claiming it is.
Please advise.