Those 9mm AR's are interesting weapons. The company I work at does all the lighting, 12v electrical and radio work on the majority of the police cruisers in our area minus the state highway patrol (they have there own person) Anywho, one of the local Sheriff's was in and got the oppertunity to check out his Tahoe setup in his cruiser we just put together with a big single drawer tough box in the rear. He had a M16 the was the select fire with burst mode, a 12 gauge and another AR type weapon that was 9mm with the fun switch (full auto). Very cool gun and the mags did look like the glock type. I didn't take a close enough look to check out the brand of the weapons but they were the blued receivers. Might of been colts but hard to tell and I don't know if they make 9mm's. It would just seem difficult to me to try to fit them small pistol mags into an AR receiver and they look kinda funky. Interesting setups though and I would definitely take one in .40. Sorry for being a little off topic but just thought it was cool so I would share.