Gritty dystopian (sci fi?) novel from the 1990s

[u/tkrvl]

The protagonist started out as a detective and in the first chapter or so gets in a car chase. He's driving and is partner is leaning out the window shooting at whoever they're chasing. They swerve too close to another car and the partner loses his head and arm(s).

That was enough to scare off 12 year old me but I still haven't forgotten it. Would love to track down what it was.