Battlefront is showing off their new self-propelled AA Gun Platoon for Flames of War in this article.
From the post:
The whole of 304. Heeres-Flakartillerieabteilung (304th Army Anti-aircraft Artillery Battalion) is self-propelled, even its 8.8cm heavy anti-aircraft guns. The battalion also has more of these guns with twelve 8.8cm FlaK37 (Sf) self-propelled guns instead of the normal six ground-mounted weapons.
The 8.8cm FlaK37 (Sf) self-propelled gun mounted the 8.8cm guns on the 18-ton carrying capacity Sd Kfz 9 Famo half-track, which is normally used as a armoured recovery vehicle. With up to 14.5mm of armour on the cab and a large gun shield it is protected against light weapons.