that study is done in the UK. and perodua, being a new company, it's least known as compared to other companies, namely proton which has been aggressively promoting there.
just my opinion though, nothing solid to back it up.

Porsche is using the boxster engine which produce less noise  JMHO. But i m suprise that 5. Vauxall is in the list while this is not a common car.

in the UK, anything japanese (except for lexus) means value for money. they prefer conti cars.
Porsches produce far more cars than ferrari and lambo and are cheaper. and they strike a balance between handling and comfort. some ferraris and lambos can be considered too hardcore. porsches are comfortable enought to drive on a regular basis without having to see the chiropractor every week.
vauxhall is popular in the UK. sort of a mom's car (the corsa). GM just neglected the malaysian market (considered too small to be important enough. not to mention the taxes wouldnt help sales)
the mini is considered a real estate agent's car in the UK. lol. and its not really a British icon nowadays. owned by germans, using a peugeot engine(new mini cooper S)? lol.

Does Perodua even exist in UK soil?
I'm sure Daihatsu is a more logical brandname choice.