hello Grief
Actually
your experience with driving shouldn't severely affect your choice
of car... i guess what's most important is to drive carefully yah?
Nothing shld happen in that case... and if anything does happen,
it'd be an insurance issue rather than a new car/old car issue. A
new car is definitely more worth it than a used one, unless you are
on a tight budget and would want to get more car (metal/size) for
your buck. People used to buy 2nd hand to avoid the mandatory 30%
downpayment for new cars. Now that is gone, and also how new car
prices have dropped, it's definitely more worth it to get a brand
new one.
Made in Thailand shouldn't be a problem, as many forum users have
said
due to
the AFTA, more Japanese manufacturers will be assembling their SEA
cars in Thailand. The City/Accord (City is a 5-door Jazz)
Vios/Corolla/Camry are built there already. Major parts and the
designs still come from Japan, but labour, component, logistics
costs are lower.. so why not?
Mazda 323: The replacement model's coming in next
year. These are leftover stock the local dealer's trying to clear.
It's up to you whether you fing this worth it or not.
Hyundai Matrix: Low price for a 1.6l car... though
i reserve my comments on Korean cars, I believe it's under-powered
and the rear seats are tad too small.
Nissan Sunny: Another popular car, though I agree
with you that the rear looks ugly. It's supposed to consume a lot
of petrol, if that's an issue with you. Actually rear drums aren't
bad ideas, they are just cheaper than disc brakes. 
Proton Wira Avoid at all costs! An early 1990s
Lancer and if you are looking for reliabililty, don't look at this
car.
Manual or auto? This is really up to personal
preference. If you'd like a manual, my advice would be to borrow a
manual car and drive it around for one day to gauge the feel. Hah,
as for not wanting to drive a manual after using an auto, well it
depends on whether you'd want to or not! An auto is definitely
easier to drive, but I still prefer manual cars... heh.
Good luck with your choices!