Lol, I agree on above statement.

To avoid being con, do your home work, short list the model you want and know it really well. When you were there, only look at the model in your list and check all the features, test drive, you can even demand to send to your own workshop for inspection.
Never let the sales person to recommend you other models, never being rush to pay on the spot, always tell them "let me think about it". Visit more shops like that for the same model, Cheras, Jln Ipoh, Sg. Buluh, ...
If you can do that, chances of being con is less.

Good luck.

Homework:
http://en.wikipedia.org/wiki/Audi_tt
http://www.mudah.my/li?fs=1&ca=9_s&q=Audi+tt&cg=0&w=3&st=a
http://m.oto.my/cars-for-sale/?keyword=audi%20tt

Also check out official Audi:
http://www.audi.com.my/etc/medialib/ngw/se.../tt_pi_2_0t.pdf
Check out per owned http://www.audi.com.my/sea/brand/my/used_c..._pre-owned.html

Test drive the new car at Audi, then can start visiting Naza, Bxxx Sxxx shops and listen to the Sales man talk and test drive. At this point you should be able to tell what is what.

As far as I know, Audi mileage is not so easy to temper with, you find a work shop that has a VCDS software and cable, connect to the car, everything will come out, even check if the ECU being upgraded or not. Stage 1, 2 or 3. The VCDS is a good investment if you have a VW or Audi.

Your best friend is Internet, start searching for more.

Just for knowledge, the miledge display on dash can be temper with easily but there is another storage for the actual miledge, read here http://www.audi-sport.net/vb/a3-s3-sportba...using-vcds.html
That was in 2011, maybe now some freak can change also that.