I live in LA. I would avoid Martin Auto Group.
They were once an authorized Isuzu dealer, but I called them looking for service and they were not at all interested in servicing the VX and were very rude when I spoke with them. Sadly their Isuzu days are long gone. The only dealership I have found whose service dept. was still knowledgable with the VX in the LA area is Vista Ford/Lincoln on Ventura in Woodland Hills.
I have had some transmission and A/C work done at Westside Transmission at 2050 Cotner, and they were very professional and the work was done right. Had leaking gasket after trans service which I brought it back for, and they replaced it immediately at no charge with no questions asked and were very apologetic. I have also had a good experience with West Coast Tire, who I have been going to for anything tire or suspension related for the last 3 years. They have always done good work for me at a reasonable cost. Both shops can handle much more than tire and suspension, though I have sometimes have had to help call around for parts when they were hard to find.
Good luck, and PM me if want more detailed info on either shop.