I have also noticed that the tranmissions have both a clutch and a torque converter. They should only have a clutch, as they are manuals. Also, the engine should be carburated with fuel injection as an option, as most Tatras were carbureted. Also, I have found an interesting video about a trike with an engine from the Tatra 613, but twin turbocharged, that could be an interesting tuning option for the engine. It´s in Czech though, without subtitles. The skin looks good, but could you try making a lightbar like this? or this Also, what would be really nice to have would be hubcaps like these. For the lightbar, you could reuse the lights used on the French police Sunburst, the ones from the Italian police Piccolina and Hopper could fit quite well too.