I have to say, I have bought two ex-Mobility cars and think some of the cars people are buying are not suitable for them. They do doddle around doing mainly short journeys. The first car had 13K on it and 3 weeks after buying it I drove down to Italy. We had quite a bit of suff on board but even so the car just had no go in it and struggled up some of the Hills. On the way Home we were cruising along a 60 when I had to accelerate for a hill so floored it, it was like we were getting a push from behind. This was a Vauxhall Twin-port engine and turned out that it wasn’t fully run in and the Twin-port had never automatically been operated. The car also used a fair bit of oil. After this trip it was fine and never used any oil. Our 2nd car was very similar, after a few decent trips at steady Motorway speeds you can feel the engine has loosened up and stopped using oil.
The PPF issue being refered to here and can also be found on the Hyundai Tuscon, is a well known problem also seen with retail owners. You can also find forums full of cases refering to it.
Vauxhalls Twin port engine is also widely known to be problematic where it won’t open or close, whether intermittent or permanently stuck open or closed. Again this can be verified with a simple search.
What was your 2nd car?