The next-generation Kia Cee'd wagon has been spied undergoing testing in Germany, trying to hide a front-end design that looks awfully like the new Cerato.

Unfortunately, the test driver spotted the photographer from our spy agency, and promptly reversed away out of sight, meaning there are no pictures of the car's rear.

Although this prototype wears significantly more disguise than the Cerato hatch spied undisguised a few weeks ago (seen below), the two vehicles clearly share the same front-end design and doors. If the rear of the hatch is anything to go by, we can expect that it will have the a 'mini-me' Optima Sportswagon rump.

Compared to the current Cee'd range, the new car's design will be cleaner and more conservative, despite the fact it was previewed by the sexy Proceed shooting brake concept at last year's Frankfurt motor show.

We haven't seen any images of the interior yet, though it's likely the Cee'd will get the company's latest infotainment options and driver assistance technologies, as per the latest Hyundai i30.

Like the Cee'd hatchback, the Sportswagon (or 'SW' for short) is expected to share its underpinnings with the i30 - the wagon version of which isn't offered in Australia in its latest generation.

Above: The undisguised Kia hatch spied in South Korea a few weeks ago

Earlier this week Kia released a sketch of the upcoming Cerato sedan, the front end styling of which matches up with the undisguised hatch prototype spied in Korea, and the wagon seen here.

All of this suggests the next-generation Cerato, Cee'd, K3 and Forte will become a single line of vehicles, albeit sold with different badges depending on the market.

Previously, the European Cee'd was a very different vehicle to the Cerato sold in Australia and the Forte marketed in North America, despite using the similar underpinnings.

Built at the company's Czech facility, the Cee'd featured a more upmarket cabin and efficient engines targeted at emissions-conscious European buyers. Additionally, the Cee'd was available as a wagon body style, whereas the Cerato/Forte/K3 range was sold only in hatchback or sedan forms.

Additionally, the Cee'd isn't even offered in Kia's home market of South Korea - fun fact, the K3 (Cerato) hatchback is known there as the 'K3 Euro'.

It's unknown at this stage whether the new Cee'd wagon will produced in South Korea, as well as Slovakia. If the Cee'd Sportswagon is produced only in Europe, the business case for Australia may not stack up due to higher costs, and is one reason why the new i30 Tourer won't be sold here.

Kia will reveal the new-generation Cerato at the 2018 Detroit motor show, which kicks off next week. The first elements of the new Cerato range start arriving in Australia from mid-2018.