Deejay, I think your friend is correct at the moment but in time I expect parts may become available as I suspect the box may be common to other marques.
I guess a possible advantage with Porsche is that it is possible to purchase a Porsche extended warranty for their cars up to circa 15 years and I think 140k miles, which ever the car passes first.
Generally if bought from an official Porsche dealership as a pre-owned machine they will provide the same warranty cover for a two year period.. Privately bought Porsches which have been serviced on schedule at official centres and when specified can apply to be put on to the Porsche warranty after passing an 111 point inspection at a Porsche dealership... One condition is that only Porsche parts can have been fitted to the car and by an authorised Porsche dealership...The guarantee works out at circa £1k /annum and can be bought in blocks up to three years max.
For sure my mid 80`s +8 could come nowhere near Porsche parts costs for replacement units..As for modern Morgans...?
If I could have had a Morgan full warranty for £1000/year for the last 2 years I'd have been quids in!!