Buying a car with mods is always a risk. You can get it checked out... but that won't tell the whole story. I own a modified car and I drive it very lightly... I am sure there are many people like me. However, I feel the majority of people who modify their cars drive them hard.
That being said... this guy didn't just 'modify' that car... he bastardized it. Even if he had put everything back to stock... If I knew the car was once as it is pictured in the current ad... I'd walk away. He clearly has no taste... so I've got to question his common sense in other areas. Maybe he poured sand into his intake for a quick P&P, who knows!?

 

The bottom of the front bumper looks horribly bent.