It sounds like you're referring to a concept that blends "Black Ice" (often a visual aesthetic or a dangerous road condition) with "Panzeroo Mode" (which isn't a widely recognized term—possibly a typo or a unique name from a game, vehicle setting, or fictional universe).
To understand the mode, we must first understand the words. black ice panzeroo mode
The success of Black Ice Panzeroo Mode can be attributed to several factors: It sounds like you're referring to a concept
Economic Crippling: You suffer a -20% Political Power Gain and a -15% Production Efficiency Cap. Move in the minute: Enemies lose visual acuity
For those brave enough to play it, the Black ICE Discord is the primary hub for survival tips, while players often share their "disaster" saves on the HOI4 Black ICE Reddit.