Sherdil: You'll find a lot of people in Karachi who will claim to be good at repairs.. But the truth is that rotary engines are hard to repair and take care of in Pakistan. Spare parts are hard to get as well, and costly too. I would suggest you don't buy an RX8 - specially one thats been used in Pakistan.
If you really must have the car, then please go for a fresh import, nothing else. That way, you'll still lose out on resale value but you have a good chance of getting a car that shouldn't break down anytime soon.
However, I strongly suggest going for an Accord or something more reliable. The RX8 is a great car, I personally like it a lot - but to be honest, we really don't have any after sales & service capabilities.
