The Poles came to their senses when they discovered that their Jelcz chassis for the Patriot was made from imported parts

The Jelcz truck chassis, which is manufactured in Jelcz Laskowice, is a key vehicle for the Polish Armed Forces. It is used for a wide range of tasks - from conventional trucks to Patriot mobile launchers, modernised WR-40 Langusta and Homar-K rocket systems.
Here's What We Know
The production of this vehicle for the Polish army started in 2004, but Polish observers have only now drawn attention to Jelcz's dependence on imported components. In particular, the Jelcz 442.32 truck is manufactured using MTU engines from Mercedes-Benz, ZF gearboxes and steering mechanisms, AxleTech axles, S22 armour from the Swedish company SSAB, and imported dashboard elements.
In addition, the Poles have to import a significant part of the equipment for the military of these trucks, such as dashboard elements for the cab. However, it is worth noting that the communication equipment in this vehicle is Polish-made.

A Polish Patriot. Illustration: Wojsko Polskie
The Jelcz 442.32 military trucks are being supplied to the Polish army under a 2022 contract, where the price of one vehicle was PLN 1.5 million. Today, this cost may be higher, and experts note that a significant portion of the money goes abroad through the import of components.
These vehicles are critical for the renewal of the Polish fleet, which still partly consists of Soviet-era vehicles. Polish analysts emphasise that import substitution in Jelcz's production would strengthen the national industry and reduce the risks associated with supply disruptions.
Source: Defence Express