You are talking about the rear roll bar for the P4? Yes it will fit, But you will have to change the upper rear corner of your roll bar as it has a welded bracket that the rear bar bolts to plus you will have to get all the rear roll bars.
+1 above.
For the average Joe, the answer is NO.
For someone who can make 2 mounting brackets on the top-rear of the P2 cage.. It can be done fairly easy.
It will mount under the bed just fine.