Tim,
As someone who owns a Mercury Grand Marquis (Ford Crown Vic) with about 70K miles of recent experience on it, I have experience with American V-8 Sedans. I do not have a lot of recent experience with the Chevy brand because I have had too much go wrong with them in the past. I can't imagine owning a Chevy product in your part of the world. Southern Arizona (USA) vaguely resembles what I think you see on a routine basis and my Ford and Nissan products held up well. In two car rentals of Chey products, I ripped the front Air Dam off a brand new Chevy 1/2 ton pickup after about 1 week. There was no impact damage. Rough ASPHALT roads had vibrated the vehicle enough to cause a stress fracture in the mounting hardware and the air pressure ripped it off while I was doing 50MPH on a relatively smooth road at the time. The GMC Envoy (mid-sized SUV) had about 27K miles on it and had so many body rattles in it, I was glad I didn't own it. The wiring harness had a rub in it that caused some problems with accessory lights in the cabin and the fog lights on the front of the vehicle. I also have had a lot of bad experiences with older GM products but, they are not applicable to what they build today. In a truly urban or city environment, I suspect they do much better.
Since Toyota is a supported brand in your country, why aren't you considering a V-6 Camry or Avalon (or the African equivalent)? The V-6 Toyota Avalon I test drove had more motor in it then my 4.6L V-8 Grand Marquis which has the USA market uprated engine for "handling".

To get my car to have the same acceleration as the V-6 Toyota Avalon, I would need to do some aftermarket engine upgrades. Not a lot but, probably around $1,000 USD and I would loose some gas mileage.
If the Toyota can't match the
feel, good pull, and reliability
in its stock form with the V-6, I would spend a little extra money for some aftermarket engine upgrades to get the power where I wanted it. Light mods to bump the power should not affect reliability and those things are so easy on gasoline that I don't see that becoming a problem for you. Keep in mind though, if you go with the Jap Rice Burner type mods, all bets are off on cost and reliability.
FWIW, I would suggest you test drive the Toyota Avalon with the Touring Package option or whatever the call the African equivalent. It is a larger car then the Camry so, you have the benefits of an
American Land Yacht with better handling and interior fittings. Also, it responds well to a heavy right foot ....
