That's a very good question, GlennA. I would guess it depends somewhat on the size of the foreign market. Does the size of the market warrant testing outside the expectations of the core market? If the U.S. market is 2 or 3 percent, they may not see it as economically feasible to test for the market or design for the market.
Amclaussen; I have read articles about how U.S. car manufacturers will do cold weather testing in the Dakotas, where very cold winter weather is readily available. And very hot summer weather is available in the southwest states. I don't think the U.K. has such weather extremes readily available. (Are there U.K. climate experts reading to comment ?) So it may not be a matter of designing for a mild climate, so much as the climate where the teating is done is mild, so the failures due to extreme climate are not seen during testing. Does anyone know if Jaguar or Audi have climate chambers to similate extreme climates ?
Well, Jaguar is an expensive brand that has many issues... I would suppose that a Typical owner would want to keep a Jaguar car for several years; so that a badly damaged dashboard is inexcussable! Poor, insuficient design and testing by Monkeys-R-Us.
Wait a minute; if any car company designes its products for a mild climate only, it would almost be called a fraud! I would say that it is a case of SLOPPY design, more that anything. In order to withstand the required mechanical stress in this type of assemblies, both the plastic part and the metal one have to be designed and fabricated properly. Asembly fixtures also play a part, as the melting tool too. Most commonly, the metal part is badly manufactured, since the punching leaves small, sharp edges that easily cut and erode the plastic bosses that are already stressed by the assembly heating-cooling cycle, which causes modified properties, different from the rest of the molded plastic part, then the bosses break easier than desired.
Your solution (to use small metal screws for plastic assemblies is the best way to ensure a proper, well joined assembly, well sealed from rain and spray. I woul write to the car maker; otherwise cars will be made even more sloppily every year.
Clever may not be the best description, curious is. Being a design engineer by trade, a faulty design is like a challenge to a duel. To win the duel, the design modification needs to have superior durability while not taking excessive time, money or effort to implement. Realistically, these faulty designs are an excellent opportunity to baseline various approaches, observing practices that work well and others which don't.
Considering all the checks and balances in automotive production and the amount of testing required when new materials are introduced, I'm always surprised to hear that something like this gets through. Texas can be very hot, but it sounds like the model didn't account for those heat extremes. Or it was a model built for one region, as Glenn's comment suggests, but sold in another region. Some Made by Monkeys columns, like this one, should perhaps be titled "Fixed by Clever Humans."
I used to own a Saturn LS series sedan. It had the same injection molded light assemblies. It had the same failure (many stops by police for taillights out ensued). I went to the junk yard to get new assemblies as mine became pitted from the poor contact. I found a car with another harness attached to the light assembly that converted back to the more traditional plug in method of connecting lights. It seems there was a quiet recall on this. Maybe Audi has the same thing going on.
My friend is a Jaguar fan. A few years ago he finally got to buy a Jaguar. He was telling me he had to replace a part of the dashboard. His theory was that Jaguar designed the car according to the weather in England = very few hot and sunny days. So, in a climate of many hot and sunny days, the dash didn't survive. Perhaps the Audi problem is a similar climate difference effect.
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