What would cause a car that was original posted at a MSRP of around 70,000 dollars go down to around 19,000 the next year?

The car is an 2007 and its not a salvage.

 

Well, since you're asking for a medical opinion (differential diagnosis), please post you're initial assessment (baselines, demographic data, signs, symptoms, etc.).

 

2007 Audi
Originally sold at around 70,000 dollars I have found a few under 20,000
Gets 14 miles to the gallon
All wheel drive
420 horsepower
1 owner
no accidents or trauma
and its not lupus.

 

Wow. It's either stollen or the wife got the car in the divorce settlement and wants to make her ex mad as hell.
Seriously, check everything out to the last detail (carfax, dealer inspection,etc.) and if it all checks out, jump on it. I would be interested in what NADA or Kelly Blue Book have to say also.
good luck