Probably closer to a MK3.5 1.3 Fiesta as this is the exact car its based on but a much improved fuel injection system and improvements to the push rod quietened it down. The KA is just a MK3.5 in a different body and minor suspension changes.
Its nice to drive with the usual great Ford 5 speed gearbox and failry easy to fix.
If you do buy one of these make sure you buy one with a full service history if your'e paying proper money, if it hasn't been serviced for a while the spark plugs can get stuck into he cylinder head.
Also the Spannish factory in Valancia didn't seem to have the same quality control as the Deganham where the Fiestas were built. So check under the floorpan for any sign of rot. Rust is the Ka's biggest problem.
Engine wise make sure its not too rattle, a litle faint tappet sound is normal but these engines should not be as noisy as the same unit fitted to the Fiesta MK3s due to minor adjustments to reduce noise. Leave the car idling for 5 minutes when testing, make sure the engine doesn't hunt, it seems to be a very common KA problem. I've seen some of these engines vibrate so badly I am surprised the engine mounts don't give way.
After its been idled for a few minutes rev the engine to about 2500 revs for 20 seconds and watch the smoke, if its blue walk away - the car is burning too much oil.
When test driving listen out to odd rattles, the heating controls sometimes work loose which causes a noise like a tin of coins shaking if you go over rough services. Also listen out for the usual odd noises from the breaks, suspension, steering etc.
Apart from all that if you get a good one and service it a they make a very reliable car that will start first time in even in the coldest of winters.