Hi,
I am driving a Carina SI (1800cc - 1999 auto) which is my first car as well. The spare parts are not hard to find except for this one instance where I had to wait for 3 months to find a replacement for a overheated sensor connected to the 7A-FE engine, which is not common compared with the 5A-FE engine of Carina TI. However, my mechanic was able to find it himself after few trips to Delkanda! Apart from that, I never had to wait for more than 1 day to find the spares at pretty decent prices.
Not all Carina SI come with the rear wiper (my one doesn't as well) but I've seen some. The fuel consumption is around 8.5 - 9 km/l during heavy city traffic and with mild city traffic it reaches over 9.5 km/l. I haven't had an experience with it on the highway yet but in outstation driving it does around 13-14 km/l.
In summary it is a reliable, comfortable and a roomy car (also the TI). The job for you is to find a decently maintained one since it is more than a decade old. In fact I had to go in search for a well maintained one for over two months but once I found it, it's worth the effort I had to put in. All in all, in a market where 10 year old cars have hectic asking prices, a well maintained Carina SI/TI is worth the 2-2.2m in my opinion.