How many times was C3PO blasted apart, and then re-assembled in under half an hour? Please.. to think a badass warrior like Grievous would not have extra entire arms, legs, shoulder plates, components, etc.. on his ship.. We've already seen he has his own medical lab and droids.
Grievous was a seasoned warrior even as Kaleesh general Qymaen jai Sheelal. In fact, his reputation as a general bad-ass throughout the galaxy, unfortunately for him, attracted the attention of Count Dooku, who secretly ****ed up Qymaen, (aka Grievous) then, like an *******, says "Hey buddy, we can save your life and fix ya right up, but the thing is, in exchange for our help, you gotta lead my droid armies in the fight against the Jedi.." So, of course, he says sure..
Also, many have asked the question weather or not Grievous (Qymaen) is a Sith, or has force powers. The general concensus is no, he does not. He only uses their weapon..
For a long time, I agreed with this.. but recently, I think I've change my mind. I would now say, very possibly, very minor/mild force abilities.. Here's why..
When Dooku rebuilt General Qymaen into Grievous, he used a blood transfusion of his deceased friend, the Jedi Master Sifo-Dyas.
There are basically 2 main types of Jedi, warriors and clairvoyants. Both have -at least- basic training in the way of the lightsaber. Leia had mild clairvoyancy, and thus, force abilities, in that she was able to telepathically hear Luke's thoughts, and home in on his location. Leia and Han later have twin children, one having clairvoyant force abilities. Sifo-Dyas's main force ability was clairvoyance.
Is it not unreasonable to assume, that Grievous, with a transfusion of the great Jedi Master Sifo-Dyas's blood, -may- have some force ability? Perhaps not physical telekenisis or even clairvoyance.. but possibly just a heightened sense of timing or awareness, slightly super-natural, due to his new blood?..
..I mean, technically, he now does have force midichlorians in his blood, and therefore, a measureable, indisputable amount of force, however minute.
This is ALL CANON, approved storyline by Lucas himself. And theoretically, any non-force user might gain minute force abilities via a blood transfusion..
(Wiki "General_Grievous"
(Wiki "Midi-chlorian"