For years, the likes of Chevron, STP, Lucas Oil, Gumout, etc. have sold fluids claiming not only to keep your car's internals running as factory, but better, improving response, power, and fuel economy. Perhaps unsurprisingly, liquid additives that claim to aid and improve the function of other systems exist, including your own analog meat-based one. As an engineer interested in the optimal performance of any system, I invested one particular commercially available fluid additive, Johnnie Walker Double Black blended Scotch whisky.
For context, I try to go beyond the bare scheduled maintenance of my own system. I wash it daily, and while I do not wax, I suppose shaving is analogous to using a clay bar. Cancer has not infected any bodywork, but there are a few Bondo seams, giving a slight rat-rod character, even though the repairs are the result of accidents, not design. Similar to BMW's F1 engine program, I try to stress certain components to the brink of failure, hoping they will strengthen in the process. I also take it on regular drives, as not to let it succumb to garage rot.
Johnnie Walker's Double Black is a fuel additive, so I should also describe what fuels I use. Perhaps foolishly, I do not adhere to any of the popular fuel restrictions: this system has operated on swine flesh, gluten, dairy, high carbs, and high protein. Though I do try to stay away from fuels that I know will leave deposits in the fuel lines, given how long it takes to replace plugged filter or pump.
Now for the additive itself. The manufacturer and those who use Johnnie Walker Double Black claim that using the additive will not only bring pleasure to your system, it will improve communication and other forms of interaction with other systems, when used in the correct amounts. Despite the words "smokey" and "double black" on the label, Johnnie Walker did not create an additive to aid rolling coal, which was my immediate and understandable concern (despite once being commonplace, rolling coal is now unseemingly in the Western world, and almost completely illegal in Cosmopolitan centers such as NYC). I am told that some people will only roll coal when using this or similar additives, but that's a story for another day.
Despite almost every automotive system additive being sold in single-use containers, Johnnie Walker Double Black is sold almost exclusively in bulk. In fact, using an entire bottle at one will almost certainly cause your system to grenade beyond repair. This seems like a huge oversight by the manufacturer, but apparently this is how it's always been done. Luckily, many aftermarket manufacturers sell reusable containers that hold enough additive for a single use. It is possible to use the additive by itself, but most seem to mix it with other non-additive fluids, such as water, carbonated water, or the similar additive vermouth. Ice is also sometimes added upon application, though I am unsure how application temperature affects performance.
After application, performance is affected, though not immediately. The claims of improved communication and interaction are true, at least from a first-person perspective, though handling and navigation do suffer, sometimes severely. Trading communication for handling and navigation is not worth the trade-off in any situation, though it definitely is in some. It's similar to drag radials being useless on the street, but ideal at the strip, if that makes any sense. However, I did notice that many people who used the additive employed the use of a co-driver to augment losses in handling and navigation.
Overall, I do recommend Johnnie Walker Double Black additive, but only in situations where the need for social performance significantly trumps handling or route-finding, though make sure you don't pour the full bottle in the tank.