TWM is the warranty company that a lot of PIs are using now to cover the car's warranty instead of having the old system of each PI having a workshop to look after the cars they sell. the car is sold together with the warranty, usually 5 years & 100,000km, and sticks with the car so even if you sell it its transferred to the next owner, unlike many of the old PI system.
and since the cost of the warranty is already fully paid for by the PI to TWM when you buy the car, all you got to deal with from now is TWM, no more dealing with the PI that brought the car in.
works well both ways i guess, the PI no longer has to worry about aftersale servicing, TWM has the economy of scale and quite a few workshop under its authorised list (i think BVO is one of them) and buyers dont have to deal with the PI and fear them closing down anymore.
and as far as i know, first automobile and quite a few other PIs offer this when you get cars from them. i got my car from first auto a couple of years ago, and so far i have no problems with TWM and their servicing. couple of my friends have done claims for things like O2 sensors, doors and windows stuff before, quite fast and painless experience.