The car is certainly underpowered for 55 HP for 850kg of empty weight. In addition the acceleration is poor. It is more like a diesel engine rather than gasoline. I measured 18 seconds to reach 100 km/h.
It consumes 8-9 liter/100 km in highway and 10-12 in city. A fifth gear can increase the fuel consumption though. But I don't think it worths changing the gearbox.
Overheats in summer in city and it has no electric fan in front of the radiator. I had a temperature gauge put on after I bought the car. Just turn on the heater and open the windows, it really helps.
It leaks engine and transmission oil. After fixing that it only goes for a couple of months then starts leaking again. I check the oil frequently.
Body is prone to rusting, I found no ways to prevent it, but painting all over when rusted too badly.
It has vibration in third gear under load, and the cabin has amplified noise at the rear. Overall the car is extremely noisy in highway at 90km/h. Although poor noise isolation helps to determine if something goes wrong.
The engine is very reliable provided that oil level and cooling water is checked.
It can be run in rough terrain. I would say it is more like an off-road vehicle, high from the ground.
I really enjoy cornering with it, though it rolls quite a bit. Even it starts to slip it is controllable. I would say it has better handling than two other modern cars I drove.
The engine had no problems except there is a little pressure drop in one of the cylinders. There was no oil burning until now.