take an arduino pcb board, like the $2 one above
solder pins on the bottom to interface with your chip. make minor adjustments so they all make contact and make sure you install it correctly (or add a fence).
the pins are here:
Arduino - PinMapping168
I would up with pins on 1-3,7-12, 17-22,26-28. I bent them out a tweak then back in on the ends and filed an inside chamfer so it pushes on nicely.
install 6 isp pins on top.
connect programmer, tweak your programming software, enjoy.
Could probably do in car, but easier to bring it in to your computer.
If you use pcb with usb then you can interface with rx/tx as well (pins 2 and 3 are touching)