Sorry, I wasnt very clear. The actually kit itself fits fine in my dash. What doesn't fit right is my pioneer deck in the actually kit. Its very loose and won't stay put.
hmm im pretty sure its the cage then..
i have an alpine head unit and they use different style cages than other brands, so if you use the wrong cage they'll barely hold it on and the head unit would just slide through the dash kit..
but i dont know about your pioneer..