Yes you are right. Its there for burket :P. I did not have the privilege of having this information before. But its giving a lot other features than your mobile phone. An excellent touch screen with all the stuff needed for good DVD and Audio playback in an automobile. But seriously speaking I really bought it as a GPS device. Alas! it just supports GPS but does not have it! what an irony. I have not researched fully in it. If this device has GPS than it must be connected to satellite. If it is connected to satellite to have current spatial point than maps can be easily installed into it. but I have found no help about it whatsoever.
Yes I have put the boot light. No I do not have any plans of replacing mirrors. Mirrors, although no retractable, are already operate-able from inside and thats enough for me. No the security system does not provide key-less boot opening but I have got it connected. i.e. opening boot activates alarm.
Frankly speaking brother its interior is the worst in city series. It just looks like local made stuff. I am also facing difficulty in keeping it clean. They have lowered down its quality to decrease overall price and increase profits. 2005-06 Civic interior is way better than city. (I am talking about quality of material)
Your both questions are highly technical. Frankly speaking I don't know :-(. Somebody else will have to answer it. Original stock tires are 175/65 R15 and I have 195/65 R15. So there is a 20 mm difference. One more thing, in Australia same Honda city is being sold with 185/65 r16 tires. This means I have 10 mm difference from those as far as width is concerned, but they have even larger radius.
As a layman I can see that, a tire size depends on radius and width. If radius is increased, vehicle's body is lifted further from the ground. So, it will help when car is heavily loaded. It will not touch the elevated ground like large speed breakers. But radius more than a certain limit will decrease ground grip. Larger the distance of vehicle's body from ground lesser is its grip to the ground. When width is increased, it gives better grip to ground. But, very larger widths lower down the car's maximum turn angle. Larger tires also make car heavy and it affects fuel efficiency. So, there must be a very good balance between radius and width.
This is all information I have. My car till now is not tested with heavy loads. Until now its just driven with maximum five people without any luggage. It turned perfectly well without any hitch or snag.
Best of luck