Hello and wellcome,
If I was to buy a rack..bars really for my meg 3 coupe,I would go for the thule version, brand name and quality.
Altho not ideally suited for roofracks/bars ,a sports car like the meg 3 coupe ,similar to a ferrari or porsche has to have some provision for skis at least
The 4 door versions especially the estate are more designed for "load racks" and have proper mounting points.
The meg 3 is a volume seller and the coupe also, Id be fairly sure the fitting is still available.
Check the manufacturers own site, as I have done for other items.
From your link..the thule bars are designed for a max load of 75 kg,however with a kit for meg III coupe fitting the max load is 50kg ,about 100 lb.
That would cover an evenly distributed load and inertia in cornering etc but air resistance and x winds.. who knows.
The pin holes are there on the return edge of the doors ,same as on an RS probly(none at rear quarter window of course) but that isnt much of a load capacity and would be scary as all getout with something mounted on the bars that was of any significant size(x winds).
I was joking about meg 3 coupe and porsche/ferrari carrying skis to st.moritz etc, but an rs 250/265 wouldnt be too out of place
Fitting bars themselves however dont seem to be suitable for much more than skis ie something comparatively light and low profile that cant fit inside the car.