[s-cars] Radio Code

[Tihol Tiholov]

> The work "CODE" never showed up after having boosted the battery the
second
time, unlike the first time. Pushing the on/off button did not do anything.

Both events - boosting a car and blowing that rear radio fuse - coincided
once IME, when I reversed the polarity (unintentionally) on the receiving
car (boostee?).  Instant glow of the wire hooked to grownd and immediate
disconnect followed.  Luckily that was the only damage, only on a new bug
it's harder to pull the radio out, esp. to fabricate the special tools.