DIN is a measurement system for interchangable
components.
Basically I think it means that most
European (and Japanese) cars have a
slot for the stereo that will accept
other "DIN sized" stereos.
There is probably some # that goes along
with DIN, but I think there is one common
size so they just refer to it as DIN size.
Also I have heard of "double DIN" or
"half DIN stereos".
I don't know for sure if the IS300 has a
DIN stereo, or a custom size. If it is
DIN, you could (in theory) pull out the
stock stereo and replace it with an
aftermarket unit.
There are "DIN NAV" systems that are the
size of a "regular" DIN stereo, and when
you push the NAV button a motorized arm reaches
out and presents a GPS NAV LCD panel.
Alpine DIN NAV:
Clarion:
Kenwood:
Blaupunkt with small display:
Alpine (not DIN sized)
Magellan PathMaster (not DIN sized)
Link to Matsu****a DIN Sized Navigation/DVD player
Panasonic
Alpine Navigation Q & A