Hello,
Sorry, my message will be in English.
This thorough test is interesting. But I'm not sure it will serve our cause as XM owners.
Remanufacturing parts is a very difficult and expensive business, with high risk taken. I know it with strut tops. And all old car owners know it. CX-Basis knows it well, so does Chevronics. Finding perfect parts is nearly impossible, even with original providers and tools when they still exist (that's the main struggle of L'Aventure Peugeot Citroën DS, they have been struggling for years with original parts whose tools, formulas and factories are by miracle still there, which is the case of perhaps one percent of the parts we are missing - but they can't have them right).
This part is not perfect. No remanufactured part is perfect. Ever. We try and all do our best to get good ones and that's already quite a challenge, especially for small batches that won't be built the same way as batches of thousands were.
But our cars are not perfect neither - even with the best maintenance possible. Try to check how your rear axle behaves... I tested NOS, refurbished and old strut tops rubbers, compared them to the original specification that I have for the Xantia : they are completely out of any specs in terms of rubber behaviour (ours fit to original rubber specs, at least after a year). That's one of the main reasons any Xantia Activa can't be even close to the original moose test result. Ever. Even if you find NOS 20-year-old rear axle bushings. They are rigid, the car lost a major part of its agility due to the self-steering effect. Same goes for engine mountings (old ones will never match their original specs, aftermarket ones are mostly bad). Same goes for spheres (membrane quality, paint quality, damper variety reduction, etc.), for ball joints,...
Our Xantia strut tops will - I hope, and I work hard for it - and all the parts we try to gather and reproduce are as good as we can do them, as close to original specs as we can. Same will go for XM strut tops (but these ones are not mine).
So are these lights. Compared to many XM side marker lights on cars today (even good-looking early ones !), that mostly want to crack when you touch them, they are way better. Compared to the latest original Valeo series (2015), with white glue pouring outside the light,... they are not bad. Compared to a broken part that some people in France have been looking for months to pass their technical inspection, that's infinitely better.
We won't store our XM's outside today, because if we do, we know that side lights will not be our biggest issue, among parts that are difficult to find (chrome trims, door and rear window seals, corrosion, etc.). That way, they won't age the same way original ones, on cars that were used daily 20 years ago, sleeping outside, did.
These NOS parts are quite rare (if you have a good source, that's good news and we have lots of candidates), and I would encourage the effort and risk that Technocitro took reproducing these parts, especially for a car that is not common and whose numbers are still quickly shrinking.
Yes, your report is amazing.
But if we want parts at all, we will also need to accept that they won't be as perfect as original parts, only "good", and appraise them for that. And that's what comes with all classics except when manufacturers maintain parts availability for long, ask any SM or DS specialist. The risk is to have no other part at all if people don't buy and keep fighting for hypothetic NOS parts, keeping their worn parts, rather than using new "good, yet not perfect" ones.
I have new parts in stock for years now, so I don't need these ones but I would definitely sign and say : THANKS Technocitro for making them widely and easily available. They are a good step forward.