I don't think a 3D scan is a bad way to go but it has some disadvantages. The main one is the 3D model must eventually be converted into a physical shape from which you can pull your molds.
This involves a LOT of extra time, work and money. Also, if this stage is not done correctly, it can destroy the accuracy of the original scan.
3D scanning equipment can be expensive. Scanning is also a very specialized skill. It is a skill I am still trying to master.
You're right, I contacted companies in regards to scanning vehicles since they're specialists and they have said vehicles aren't easy. If you want a very high level of accuracy, even a $25k machine like the Arctic Eva won't cut the cake. It'll make it close but not if you want it nearly dead on. Also you would need 2 different machines if you want to do the outside and inside correctly. These machines are over $100k each so buying would be out of the question. Thankfully you can rent these machines for about $5.5k a week and that's without training which requires maybe 3-5 days and is about $1.2k per day.
Plus you run into the problem of scanning panels accurately, not the faces but the sides to make sure you have the correct thickness of panels. It's not a problem with the machine itself, it's the actual software that a highly skilled specialist has to deal with and that's no small learning curve for an everyday Joe to master. If you have the hire a specialist, expect to pay over $100 per hour for that service alone.
So realistically, either getting your hands on the actual vehicle and splashing the actual thing or going with a 3D model someone made off the internet which is a hit and miss because I've been trying to track down the most accurate model and no one can say how accurate their designs are considering they're getting their models off of various sources such as pictures, maybe model cars, etc. I haven't found one that has done a 3D model of actual measurements off the real thing yet. I doubt if they did, they'd be willing to give it up for cheap. The cost of replicating a vehicle
