While we recently confirmed that Mercedes-Benz is planning to have an aftermarket CarPlay solution for older vehicles out by the end of the year, some of Apple’s other partners aren’t as confident. The two other companies that have so far announced the feature for new vehicles— Ferrari and Volvo— are both hinting that aftermarket CarPlay solutions are probably not happening anytime soon.

We reached out to Volvo about its aftermarket CarPlay strategy and the company told us there are “major roadblocks” to overcome before it commits to any plans for older vehicles:

While Mercedes-Benz seemed pretty confident that it would be possible, and there are no clues that Apple is preventing it from happening, it sounds a lot like aftermarket solutions aren’t a sure thing for all CarPlay partners.

Ferrari flat out confirmed that CarPlay will NOT come to its older vehicles in a statement to AppleToolbox today:

What roadblocks could Volvo be referring to? When it comes to a usability point-of-view: The newer vehicles are being designed specifically around the CarPlay system. That means physical buttons and dials on the dash and steering wheel of new vehicles have been specifically customized to provide an easy-to-use experience with CarPlay. The touch displays being used are also specifically optimized for the experience. Due to this, an aftermarket solution is more involved and likely much more expensive than a traditional in-car infotainment system.

A Volvo representative we spoke to told us a little more about the difficulties with creating an aftermarket solution:

After Apple officially took the wraps off CarPlay, its new iOS feature that displays core iOS apps on in-car displays of select vehicles, only the three companies mentioned above announced when the feature would come to new vehicles. While iOS 7.1 officially flipped on the switch for the feature on the user end, Mercedes-Benz, Ferrari, and Volvo won’t bring out new vehicles with the feature until sometime later this year. You can also expect an announcement soon from Toyota after the company briefly leaked plans yesterday to bring out the feature by 2015. Apple has previously confirmed other partners as well that have yet to announce availability, including: BMW, Ford, GM, Honda, Hyundai, Jaguar, Kia, Nissan, Subaru, and Suzuki.

Earlier this month Mercedes confirmed to us that it is planning an aftermarket solution by the end of the year but didn’t provide any other detail on pricing or availability.