Undeniably one of the most iconic and easily recognisable vehicles ever, the Volkswagen Beetle still has a really strong cult following around the world, remaining fairly usual to spot one serving to its original purpose as a family vehicle in countries such as Brazil or Mexico. Despite fewer other cars with a rear engine also achieving a comparable success as a regular runabout, the Beetle also got a substantial attention from the aftermarket, including all sorts of performance upgrades ranging from engine tuning kits to complete engine swaps, occasionally sought after by some people who daily-drive an old Beetle for reasons other than performance alone. While certain engines more often swapped into a Beetle with many different degrees of complexity have been tried and tested, there is a great opportunity for something specific to cover such a wide and diversified market, which actually goes way beyond the usage of the Volkswagen flat-4 engine for automobile applications, from specialty equipments to ultralight and light sports aircraft resorting to either a modified Volkswagen engine or something clearly inspired by it.
Most likely, a nearly "perfect" way to address nearly all those user cases for Beetle engine replacements could be a dedicated engine based on that LiquidPiston's X-Mini rotary engine design, yet a larger displacement on each rotor housing and some adaptations to enable twin or triple rotor setups would be desirable. As the LiquidPiston single-rotor designs usually feature the intake duct and exhaust outlets on the same side, that would render it harder to develop versions with 2 or 3 rotors, so a redesign with the exhaust ports on the opposite end-plate would be the way to go, while the hollow eccentric shaft which also doubles as an intake manifold is much harder to get rid of, yet maybe with a greater amount of rotors it would be worth to look out for other layouts... But anyway, as the only rotary engines to effectively become successful from a market standpoint, back in the day when NSU and Citroën joined their efforts to make Wankel engines while Mazda tried on its own to replace piston engines of its entire range with a basic Wankel layout prior to the oil crisis, always had 2 rotors, it's a historical precedent harder to overcome than most technical challenges which may be held against the real-world viability of an automobile engine developed according to a LiquidPiston basic project.
As the Volkswagen Beetle is still embraced by so many people around the world for the most varied reasons, with engine swaps also playing an important role for the enthusiasts and "traditional" users alike, the opportunity for a dedicated engine platform to cover this and other applications for a lightweight and compact powerplant is clearly outlined. The possibilities to venture into engine swaps for cars other than the Volkswagen Beetle, even if the specific benchmark for a development based on a LiquidPiston design would still be the Volkswagen Beetle, may lead to a quicker return of investment, considering all those other cars originally fitted with some engine frequently adapted to Beetles and derivative models from both Volkswagen and so many low-volume automakers who resorted to the flat-4 as an off-the-shelf powerplant. So, even if at a first glance it might sound pointless to look at the Volkswagen Beetle as a testbed for a modern engine, in the end this might be a quite promising opportunity to venture into...
