5 cars which could be an interesting testbed for a 2-rotor engine based on the LiquidPiston designs

With a different approach to the rotary engine, which is more reminded by how Mazda took the Wankel concept and turned it into one of the most relevant parts of its brand identity, the startup LiquidPiston is a proponent of what could be described as a Wankel turned inside-out in order to effectively address its downsides. So, unlike the Wankel layout which resorts to triangular rotors inside oblong housings, with 3 variable-volume chambers at each housing where different stages of a 4-stroke combustion process is undertaken, LiquidPiston has resorted for both spark-ignition and compression-ignition engine designs to an oblong-shaped rotor inside a housing containing 3 constant-volume chambers where all 4 strokes happen in a way analogue to the cylinders of a conventional reciprocating engine, yet only single-rotor variants of its proof-of-concept engines had been showcased. However, just like only Mazda achieved commercial success only with 2-rotor Wankel engines (and even a twin-turbo 3-rotor to a much limited extent), most likely a mature LiquidPiston-based engine would only achieve commercial viability once it could be scaled-up to 2 or 3 rotors, with 2 being more likely to happen considering the weight savings intended for the design and some odd features such as resorting to a hollow eccentric shaft (analogue to the crankshaft of a reciprocating engine) to guide the intake charge, and among so many cars which can be interesting testbeds for such an engine I could quote at least 5 without a doubt:

1 - Renault Kwid: originally intended to be made in India, this budget-oriented model also became available in Brazil from 2017 on. Considering its featherweight nature, and how it was intended to be a fairly inexpensive "people's car", the claimed lower overall cost to manufacture a LiquidPiston-based engine and its intended fuel-efficiency would be a perfect match, once its scalability and lubrication of the eccentric shaft get properly addressed;

2 - Peugeot 208 (second generation): even though forced-induction had been taken more seriously at an earlier stage in European versions than in its Argentinian-made counterpart, to which at first only the ancient naturally-aspirated 1.6L EC5 engine had been offered, until the 3-cyl 1.2L EB2 also became available in Argentina and Uruguay, while the 1.0L Fiat GSE engine had to be specified only for Brazil in order to benefit from a tax break for 1.0L-engined cars. A lower cost and the simplicity of being able to resort to a single engine with fewer parts, at a more favored displacement class, yet with a better power-density, would be beneficial;

3 - Chevrolet Montana (third generation): the oil-bath timing belt on itself is enough to justify the will to fit another engine without this controversial feature. As the Brazilian-made turbocharged versions of the GM CSS Prime engine retain port-injection, unlike its Chinese and Korean counterparts which resort to direct injection, is also subjected to criticism in Brazil, so as a LiquidPiston engine tends to feature a higher power-density even with natural aspiration it would most likely remain proportionately cheaper (at least in theory), not to mention how turbocharging an engine makes it more critical to not paying attention to lube oil specifications;

4 - Ford Pampa: most noticeably the rare 4X4 version, which could be more specifically interesting as a testbed for a Diesel engine, which could be based on the 25hp 2-stroke LiquidPiston XTS-210 engine, which has been more highlighted for its intended usage on portable gensets and military drones. Had it already been possible to stack a pair of XTS-210 engines together to form a single 2-rotor 50hp engine, comparable to the 1.6L Diesel version of Volkswagen's EA827 engine, I'm sure it would be quite easy to find a Ford Pampa owner to volunteer as a test-driver;

5 - Kombi: either the water-cooled EA-111 engine or the air-cooled boxer it replaced are far from being bad enough for someone to replace them just for the sake of it, yet it would still be tempting to pick one as a testbed for a different engine. The compact and lightweight nature of LiquidPiston designs would also render it less likely to affect too much the weight bias while unloaded, which could be a critical matter for other engines.