Outside temperature thermometer

[fixkick]

wow no year car and guess what ?,year means wire colors !!! used (was not standardize until later years)
best in what way ?, best has vast , meanings to vastly, different folks
ill guess, safe = best. (not looks or works or ??)
safely:
use a fuse do not install anything lacking an added fuse.
best way electrically would be
1: not cut factory wires ever, why do harm? (so pick radio)
2: the only questions is where to get power, to it, one way is a ugly cigarette lighter adapter, nah....
2b: Id use the radio wires after all that wont do damage, to EFI critical circuits (this year)
2c: the radio has 3 power wires, 1 is good, the bad is lamp dimmer wire the other 2 are main power, and battery memory power wires, the mem wire is hot all the time and no good.
the radio, main power is called Ignition on or ACCessories,
I wire to this wire, with my inline 1amp fuse to your red wire.
the black wire is grounded to suzuki body ground lugs (any)

if you had new aftermarket radio, and with that nice adapter kits that to that, then you'd have all the information you need to wire to the radio side,
wild guess on year, by me ! (tossed dice)
1996, (white/back is it)

Car Radio Battery Constant 12v+ Wire: White/Gray
Car Radio Accessory Switched 12v+ Wire: White/Black put an inline fuse to here 1amp fuse,
Car Radio Ground Wire: Black
Car Radio Illumination Wire: N/A (parking lamps)
Car Stereo Dimmer Wire: Red/Yellow (dash dimmer lights) super bad way.
cut paste partly.