Some cars do seem to eat CV boots for some unknown reason. One of my A6s had a string of them before I got it then didn't need another for 130K after I changed them myself.
I presume you are using good quality boots? The Lobro GKN ones from Euro Car Parts are OE, last very well and are cheap
Link here:
http://www.eurocarparts.com/ecp/c/Au...77eb70b&000445