Speaking on a global level, Saturn is now officially aligned with Opel/Vauxhall, which also shares a few models with Holden as well. With this deal we will likely see that as the chassis are replaced or updated, the Saturn lineup won't look too different than what is made available by their corresponding partners in the UK or in mainland Europe. Basically, it will be a process that will take several years, but it is already underway, clearly with the Aura (Vectra), VUE (Antara) and Astra (duh).
As to what I've understood will be happening:
Astra: The Astra as we know it right now will have a roughly three year stint in the US as the Delta-II model of the car is being designed. Built in Belgium, it will start arriving in the United States (at full capacity) officially in January, but some may sneak in well before then. The two-to-three year run won't likely see many changes outside of the possible addition of a diesel model and the near-certain Red Line version likely with the 260 BHP DIG I4 from the Sky Red Line. The updated Astra should bow in 2009, with an all new chassis, engine, and transmission lineup... Which will likely carry over the same basic options of several petrol I4 models, at least a diesel I4, a high-performance Red Line version, and presumably a hybrid as well.
Aura: The Aura as we know it will likely have a short lifespan as well. The next-generation Epsilon-II cars are already being tested in Europe to replace the current Vectra, so while that version may be due in 2009 across the Atlantic, we'll likely see our next Aura debut as a 2010 model. It will be a bit larger, a bit more roomy, will likely have more power, and a Red Line version doesn't seem out of the question. Diesel power and hybrid power is also a near-certainty as well. The larger question will likely be how the updated Chevrolet Malibu and the Epsilon-II Buick LaCrosse will effect it, as the Saturn must split the difference between them (remember; The Pontiac G6 is going RWD post-2011).
VUE: Don't expect much to change anytime soon. The only update I've heard coming down the pipe was the addition of a Two-Mode hybrid (similar to a Prius or Tahoe Hybrid), and presumably the addition of a six-speed automatic on the four-cylinder models. As of right now, I'm not sure if there are any plans to update the Theta chassis in the near-future.
Outlook: The Outlook has done marginally well for Saturn, simply put, the Buick Enclave has stolen the show for the Lambada triplets. The only major concern will be the new Chevrolet Traverse stealing too much of it's thunder, but outside of that no major changes are expected any time soon. My guess is that a DIG V6 will eventually be added, the styling will be updated to match that of the new Aura (come 2010), and the big rumor is that there may be a CUT (crossover utility truck) coming sometime soon.
Sky: All that I have heard as of late is that production of the Sky and Solstice will be moving to Bowling Green (alongside the Corvette) in the not-too-distant future. No major changes are to be expected, although with the Solstice likely receiving a coupe or targa option, I'd suspect the same for the Saturn. The big question is likely over how the Kappa chassis will survive as there are two main theories;
1) Kappa sticks around, moves to Kappa-II around 2012 or 2013, and may spawn some kind of Corvette... Likely depending on if the "true" Corvette stays FM or goes MR.
2) Kappa dies-out and gives way to the Alpha chassis, which will allow for a cheaper basis for a next-generation Coupe/Roadster.
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What would I like to see added?
The Corsa: All current plans put fourth by GM and accidentally leaked by the UAW point to the US getting a small Gamma-based vehicle for 2009 or 2010. This would likely mean that we will have a Corsa, no word on if the name will be the same, and we may in fact build the cars for other parts of the world if the dollar remains as weak as it is. I'm crossing my fingers for diesel power, as well as a light-boost turbo model, but we'll have to wait and see.
The Zafira: Similar to the Corsa, UAW contracts say that we're going to be building a Delta-II MPV, so its pretty much a case of connect the dots I'm afraid. I am uncertain, again, if the name will remain the same, but I'd suspect a diesel and turbo version, and possibly even a V6 should the Americans get their way when designing the vehicle.
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Lingering questions:
Q: Will Saturn get a Zeta model like everyone else seems to be?
A: No, probably not. Pontiac will likely end up with the most RWD offerings, Chevrolet with (presumably) just the Impala and Camaro, Buick with only the Park Avenue and possibly Velite, and Cadillac with their STS and DTS replacements. Saturn, much like Saab, will remain Zeta-free.
Q: What about Alpha?
A: Alpha seems like a more-likely chassis should Saturn/Vauxhall/Opel decide to do a small RWD car, but generally speaking, I doubt it happening in the US. The only Alpha Saturn we will likely see would be the Sky successor, that is, if they do not develop a Kappa-II chassis.
Q: What about trucks?
A: Its a tough question, but I'm under the assumption that Saturn will only offer the Outlook and VUE for the foreseeable future. Should Outlook sales slump too far, my guess is that only the VUE will remain, allowing for the Zafira to pick up where the Outlook left off.
Q: What about alternative fuels and hybrids?
A: Its a tough question because GM wants Chevrolet to be the volume-brand (like Toyota), but wants to make Saturn seem like an upscale brand that everyone can afford as well. My guess is that the Volt and all of it's stuff will remain Chevy-exclusive, will be sold all-over the world, and everyone else will have to get by on Two-Mode hybrid systems. The Two-Mode changeover won't likely come until closer to the end of the decade (knowing GM, it has to become cheaper for them to produce before they offer it everywhere). The only other change for the "greenies" would be diesel power, which I suspect would be GM's leading brand in the United States.
