Buy and export a car from Romania

Hello everyone,   

I''m from Greece and I want to buy a car from Romania.   
The car is a dacia duster and I find a lot of ads here due to the factory I suppose.   

I have some questions about the process if anyone who speaks english and knows could help me! 
Should I trust private sellers who say they are the first owner and not buy a car from germany or whatever?I suppose the inspection company can find it in papes...
 
As much as I know from Germany mainly if I buy a car from a private seller:   
1)I have to go to the embassy to make the papers! 
2)The seller has to deregister the car 
3)Some technical car  papers 
4)Temporary plates and insurance   
Is anything else I'm missing?   

Also I found this company to test the car I would like to buy: https://inspectorauto.ro/ro/inspector-pe-teren/ 
Is this a good choice or there is something better?   

Is the hole progress easy, can it be done in one day, temporary plates, deregistration etc.. with all the paperwork like in Germany or Austria?   

Because the Greek embassy is in Bucuresti I have to find there the right authorities. 
Can anyone help where I can have temporary plates and insurance in Budapest, is it an authority or a private company? 
Will I have problem to cross the Romanian borders with the right papers(I read somewhere in a police website that the car must be on a trailer??)?   

Thanks a lot for your time and to anyone who can help me!