Ok I have been doing some research and it depends on the weapon that hits the BMP and where it hits it at. For example, an RPG that strikes the BMP in the rear will cause the vehicle to explode nicely. Most BMP have two doors in back and the doors are feeled filled with fuel, also the ammo is stored in a ring around the base of the turret. And if the ammo is hit or set off the turret explodes and flies off the BMP. Now in one of the books I have a BMP-1 was hit by a SABOT round at the base of the turret. This round did not set off the ammo and did not hit the fuel. Instead it went in the turret damaged the gun and killed the commander and the gunner. There is small hole with some flashing scattered out from the hole and the loose equipment on the BMP is knocked around. But other than that the vehicle looks ok. So. I quess what I'm saying is it depends on how much time you want to put into it. If you have the time and resources I quess you could have the turret blown off and show all the detail inside. And if not then you could go with the small hole and so on.
The two books I have that show some "ok" damaged and blown up BMP's include "The War In Afghanistan 1979-1989" BY David C. Isby And "Sword In The Sand, U.S. Marines In The Gulf War" BY Tony Engelhart And Pat Foran. Both books are published by CONCORD.
If you need detailed pix and drawning of the inside of the BMP and family check out "BMP-1 Soviet Armoured Fighting Vehicle In Detail" BY Wings and Wheels Publications, Photo Manual for Modelers. This book is by far the best for inside referances!!! And "Russia's BMP Infantry Combat Vehicles" BY Steven Zaloga and David Markov, CONCORD published.
FINALLY once you decide on the amount of detail you want, post again on the subject and I can help you some more.
(PS) I know I sent you this in a E-mail but I thought there might be others that would benefit from this info. so I posted it here as well.