well i think the TVT guys are a pretty good bunch, but if I think I do remember a previous thread about poor contact from them. But I also remember that they had been dealing with alot of things at the moment. Still, if your friend is a ASE certified good mechanic, MB/XF or not, if he has the right parts he should be able to install them and get the car running... So like oledoc said, I would keep trying to contact them, and with this thread being up they should deff. get in contact with you... Post back and let us know how it all turns out since your post is a little concerning. And welcome to the forum, throw up some pics and show off the low miles SRT6.

Kolme