As Polestar moves forward with its business plan and pushes the idea of a subscription model, the question of what becomes of a used car becomes ever more important.

With no clear path to ownership laid out like in a lease, buyers can simply return their three year old cars and wash their hands of them.

While not entirely unlike a lease agreement, there's also the question of what automakers should do with lightly used cars. The number of year-old cars that need a new home is likely to increase under the subscription model because Volvo (and probably Polestar, too) are offering to let owners restart their subscriptions after 18-months with a brand new car.

Gregor Hembrough, head of Polestar in North America talked us through some of the options the brand is considering. While he's quick to clarify that no firm decisions have been reached (market launch is still about a year away), there are some attractive options for Polestar.

One of the advantages of the subscription system, Hembrough argued, is that it can be used not just to hold on to existing customers as they subscribe to newer and better vehicles, but to attract new buyers, too.

"So [you have] the means to subscribe to a Polestar 2 brand new. My budget might be something different," said Hembrough. "However, I want a Polestar 2. So when [you] drop the keys off after 18 months here's my opportunity to step into a Polestar 2, albeit 18 months old, but with the same great experience through a Polestar Space, you're buying into the Polestar Brand and having the Polestar ownership experience."

As a result of the age and the mileage, the subscription fee would be lower than a brand new car's and you wouldn't be able to option it out quite like you hoped, but still, you're driving in a nearly new car at a discount.

After a period of re-subscription, as Hembrough terms it, Polestar wouldn't necessarily look to find another subscriber, though.

Then there's "an option where the customer can outright buy the vehicle: 'I have a love affair with this vehicle, I want to take it.' That could be one option," says Hembrough. "Number two is it could end up in a pre-owned center, whether it be with one of our partner franchises or one of partner-sister brands, perhaps.

At that point, the scenario isn't all too different from current certified pre-owned programs, with three- to four-year-old cars with fewer than 75,000 miles on the odometer finding their way into the secondhand market.