It must be to do with bumper shape or just plain cost cutting.
Because of the low numbers made VW won't have bothered engineering in anything that would have cost them much.
The specs on the cars are odd.
Ambient with leather but not with normal cloth seats.
No winter pack with normal cloth seats.
Hit and miss whether you get red edged belts...
And so it goes on.
The only ones I've seen photos of with front bumper sensors were retro-fitted. Apparently an easy job and a good idea if it's a daily driver. There are lots of things sticking out of the front bumper that are easily damaged if you're a bit tight on space. I tend to try and leave about a six foot gap when manoeuvring! 
Other variations include lack of 'clubsport ' honeycomb grill pattern trim on dash and doors and lack of illuminated 'GTI' lettering on stainless steel sill plates, not just the red lined seat belts.
I like my clubsport (thanks to the nice engineering, no thanks to the half arsed efforts of the ignorant and disregarding corporate side!) which doesn't have red lined seat belts, regular patterned door dash inserts WITH illuminating red lines (as Vienna leather), illuminating red line(not 'GTI') on sills... (newer type slimline rear view mirror too interestingly)
I definately think that run-out pre-registered clubsports at vew dealerships were these interrior poverty -spec cars
VW UK wasted my time and did not admit to any of this despite me presenting loads of email evidence with links of UK clubsport cars that have the correct specs (not just the bucket seat models).
Theres a clubsport for sale at VW Colindale without a black roof, with honeycomb clubsport dash/door inserts (these never seem to be illuminated) but WITHOUT red lined seat belts. I saw it there for sale a while before, then relabelled a demonstrator, now for sale again!
My detailed correspondence with such references involved vw UK /germany/ and cc'ing the office of the CEO (Mattias Mueller)was essentially ignored consistently and no answers provided to why there was variation and omission of features in various models. Very disingenuous and non-transparent behavior from the organisation
VW Germany even said they thoroughly investigated but would NOT tell me any of the results OUTCOME other than to see what VW UK would say (also nada). All I wanted was a truthful explanatory answer
I get the impression UK VW customers get poor service/consideration compared to other markets. No online merchandise store , closing of customer facing aspect of miltonkeynes HQ.. I bet VW Germany give German customers better customer service - - I hear VW reputation there has been affected badly by Dieselgate .
