The holes under the bungs are where the body shell is carried around the factory prior to the underbody items like the suspension / power plant etc gets installed.
They usually term both of these items coming together as the “Marriage”.
When the overhead cradle is release, these areas should then be treated with anti corrosion treatment, then the closing bungs should be installed.
When the car is picked up by the four pick up points of the cradle, the inside of the pick up points are scratched, leaving bare metal exposed on the body shell.
The bungs are fitted without any type of sealant, so as soon as they come into contact with water they rust almost straight away.
This could easily prevented by getting the dealer to remove the bungs on the PDI check and apply some sealant.
It would take no longer than 5 mins to perform this task on a ramp.
Once the bungs are fitted, then the surrounding area should be treated with underbody treatment.
The bungs never need removal again.
MG should have picked up on this issue and included this in the PDI work.
It’s not like the PDI is very lengthy anyway.
Book time for the PDI work is likely to be about one hour.
Many many years ago, I got the chance to do a brief work assignment at a car factory and was able to spend time on the production line.
Wow ..... I got to witness some interesting working practices !.
Like the time the night shift walked out ( in the middle of the night ) because somebody had forgotten to refill one of the vending machines on the day shift, I kid you not.
Cant see that happening in China some how ?.