All from Atsuko Nakajima's Tsuya artbook, all scanned and cleaned up by emu. If you take any of them, please credit and link back to http://ps.ishness.com or LJ user emukatze if possible.
Where I got it: Animebooks.com (also can be found at akadot, and elsewhere I'm sure)
Disclaimer: You really should buy the book. It's a beautiful book. The GetBackers stuff is only part of it... it's also got lots of Atsuko Nakajima's work from You're Under Arrest, Mon Colle Knights, Peacemaker Kurogane, Rurouni Kenshin, and some other things.
(notes: The first picture is the book's cover, though I scanned the clean version of it from the last page of the book because A) I'm lazy and it was easier and B) the full cover would've required stitching and, well, I'm still lazy. The car in the second picture is the You're Under Arrest girls' car (they're the girls on the cover, if you don't know them), but I didn't scan the other half of that picture that has the two girls approaching the GetBackers' car. None of the two-page spreads have been stitched together, either... maybe I'll get to it one day, but I doubt it. ^^; I didn't scan the picture at the front of the book that has Ban and Ginji with the two girls from You're Under Arrest, nor did I scan the page with the chibis or any of the character design pages. I forgot for the first two things, and I don't feel like scanning all those character designs. x_x If anyone is interested in the character pages for cosplay reference or something, feel free to email me and I'll likely be happy to oblige... just don't ask me to do all of them... and there are a couple who aren't in there.)
(Another note: Please don't ask me to scan the rest of the book... if you want the rest of the book, you'll have to buy it.)