The most common lies in Karachi's used car market, whether you buy from a dealer or a private party, is rolled back mileage, undisclosed accidental history and when looking at 5+ year older cars, removal of cng kits and claiming the car to be always on petrol.
I was in the market some months ago for a clean 8th gen Civic, budget and variant/trans was not an issue but I needed a clean car. Now my denter is a very experienced fellow and is street smart, has worked at all of our local car selling companies as a QA inspector. We checked a lot of these Civics, labeled as sparingly used and driven only on petrol, and 100% of these cars were driven on cng during some point of their lives. One car I remember was parked at a showroom, all fine and dandy, polished like a mirror, fully loaded, 80K kms done, 2012 MY. Upon checking, the car was hit from the left rear quarter, enough to bend the frame next to the spare wheel, straightened out, and had cng removed, while someone sealing and closing the cng holes with primer. Car was priced at a tag of close to 2 mil.
We confronted the sales man who, atleast pretended like he didn't know or was ill-informed, proceeding to call someone and argue about the "item" that they sent in for a sale, I spent 3 months looking for a car, never to buy an older than 5 years car again.