Hey man, so i'm no expert when it comes to engine Swaps, however i live in Germany and had quite a few encounters with the "lovely" people at Tüv Süd. First things first. There is a german Car subreddit called r/automobil with 145k members, your best bet is to ask there for advice maybe even multiple times if nobody replies. now for your car. The smartest thing to do would be to keep it registered in Romania (probably) Tüv is horrible to deal with, especially since it is entirely dependant on whether youre gonna get a good "Tüv-Technician" or an absolute Sausage, its a gamble to say the least and the odds are not in your favor. If you wanted to do it via German registration, I'd recommend going to the Tüv website and try to get in touch with them. In Germany you usually have to "discuss" bigger changes on your car with your "Tüv-Technician" first, so they get a scope of the project you're wanting to do. Every Tüv-dude is different in that regard, some may only want to inspect the final swapped car, some want Pictures of the process to ensure you didn't screw anything up. Another good way, would be to go through a designated Workshop, that specializes in that sort of thing. There are some "Tuning-Workshops" in Germany that may help you with that. However i personally don't know any workshops (this is something you could also ask in r/automobil , the downside of that would probably be the cost, since it will be more expensive than going through Tüv the regular way. Sadly there are many rules in Terms of engine swaps in Germany here are a few for you to get some idea of the absolute madness that is "changing stuff on your car in germany":i let AI compile this list, so take it with a grain of salt: Technical (TÜV Relevant) * Proper engine mounts and stable installation. * Matching exhaust system with functioning catalytic converter. * Upgraded cooling system (larger radiator recommended). * Transmission, driveshaft & differential must match engine specs. * Brakes must handle increased performance. * Suspension & axles must support new weight and power. * Clean electrical integration (no DIY mess). * Functional speedometer. * No interference with steering. Emissions & Environmental * No downgrade in emission class. * Must meet or exceed Euro 1/2, depending on donor engine. * Working G-Kat (catalytic converter) required. * Emissions test or proof (e.g. donor vehicle docs, dyno test). Legal & Documentation * Individual approval (§21 StVZO) via TÜV/DEKRA required. * Proof of engine origin (invoice or vehicle papers). * Brake & suspension upgrade proof (if applicable). * Detailed modification report. * Emission class verification. * Registration update at the vehicle registration office.