Chevy's already got the Epica and Captiva planned for the Pakistani market, both new entries will probably be in the +2-3 million bracket thanks to the Gov. tax structure. They've got the Spark that comes with more features than a Corolla GLi for half the price but our people just refuse to get it.
Cherry's got the same deal with the QQ that actually costs less than the Mehran and packs more than a GLi but people here will buy a Mehran and dislocate their joints for "market value".
It's not just the ToyoSuzuHonda trinity that's got everything clogged up, we actually need to change our own thinking. If a Mehran can sell for 50% current price even after 10 years (the only reason it's bought really), a QQ or Spark can give you 10 years of comfort on money well spent.
In the end though, it's tough for a foreign company to set up a multi-million dollar plant only to sell vehicles with no market value; the only way to secure a good position is by getting the goodwill of local mechanics who will try their best to reject any cars which require them to update their equipment and get used to newer technology. And unless you're planning an investment of a few billions, you can't set up 3S shops in all major cities to increase market share (even if you do, the investment will never pay back).