Fouad Bhai .. it is honour for me to know you and to contribute in your thread ..
I had always thought that I knew about cars .. but after joining PakWheels, it has really become an inspiration to know so many new friends, and share our common experiences, and knowledge .. I must say, I have learnt a lot, and I continue to learn on everyday basis. I must say the spirit behind PakWheels is sharing of our common enthusiasm.
About the side skirts and other external modifications, let me share experience of Laadli ... Usually, I am the only one in family riding the car every day. So weight is not an issue. However, with changes as a result of modification from GLi 2010 to Laadli, issues do crop up many times.
Even with an empty trunk, the load comprises about 60 kg (or perhaps more) of CNG kit, about 50 kg of the twin subs, and approximately 55 kg of gasoline in the tank (I always keep the tank full) ... Now all this weight at the tail end of the car, results in substantial weight increase. Now if you look at Laadli from the side, it appears that its suspension has been lowered, but this is not the case.

MashaAllah, Laadli looks very fine. But when I move with my family, I need to be extra careful. Indus Corolla cars have slightly more ground clearance than models elsewhere in the world. However, still in many areas, this is not enough. I have a close relative living in Rawalpindi ... enroute there are so many poorly constructed speed breakers. I have to slow down and cross the speed breakers diagonally to avoid touching of the vehicle underside (I learnt this diagonal crossing technique while driving my Ford Mercury .. you might have seen the photo in Laadli thread ... it was 18'6" long and crashed onto every speed breaker :P) ... sometimes the diagonal crossing is not possible due to oncoming traffic from opposite in a crowded and congested city like RWP