This "tech" they talk about already exists. It is expensive as all hell. As in, $8-10k all said and done to have installed and verified. These systems are sensitive, and must be maintained and calibrated by a certified technician rather frequently, as in one a month or more. Even then, they are also infamous for being unreliable, prone to malfunction and false readings, and causing all sorts of long term electrical issues in cars they are installed in.
Implementing these systems in all new cars would pass even more cost onto the already constrained consumer, and most certainly would be abused by the government for tracking purposes.
A shockingly high number of DUI fatalities occur from drivers that already have previous DUIs. STOP GIVING THESE PEOPLE THEIR LICENSES BACK FFS!
Keep Poking that strawman, I'm sure it'll give you a hug sooner or later.
If you are willing to give up freedom to earn safety, you deserve neither. It's tragic your friend died, but that does not justify pushing elevated cost and government tracking on hundreds of millions of people. Require those with DUIs on record to have these systems installed, sure, but not everyone, doing it to everyone makes as much sense as making everyone wear SWAT battle armor because somebody may have a gun somewhere in your city.