Panda 100hp enjoyed so far but has been tampered with previous owners...

The Fiat 1.2/60 is so under-stressed, you can thrash it all day long and it just shrugs it off.

Ditto the 900/40 used in Seicento.

Any 2nd hand car and you should watch the oil consumption, i.e. be paranoid. There are few things more basic to car ownership than checking the oil. "No oil" should never happen to anyone who knows anything about cars unless there was a catastrophic failure.

It looks like you bought a car that was "pimped". Car manufacturers spend billions on R&D to design them right, why do people think Joe Bloggs down the road can do better? In some cases Joe Sixpack is smart and improves a car for niche appeal, but more likely something will be screwed up and this type of owner has likely also thrashed it.

Only buy that type of car for money you can afford to gamble or lose and you want a project.

Has the cam belt been changed on time?

I had a Punto HGT that I knew needed a cam belt. I used the car while waiting for parts to arrive and of course than cam belt failed 2 days later. I should have known better but for sure I wont make that mistake again.

The Panda 1.4 16V is NOT A SAFE ENGINE. If the belt fails you will bend valves and might well scrap the whole engine.

I had a Punto Mk2b Sporting from new in 2005 (same engine as Panda 100hp). I used to kick it's head in everyday, to be fair it got to 130k miles without any major problem except for the common gearbox issues when it was new. But I did look after it, new oil, filter every 6 months. New spark plugs every 10-12months.

Don't think the op is coming back, maybe didn't like the advice.