Hi... I had a the same sort of problem with my Mercedes Vito because I did not want to drill any holes in the bodywork so after much thought I purchased a DAB aerial, removed the gril to the front of the van and and with the help of a metal bracket that you would use for screwing a kitchen unit back to the wall I drilled some holes in the chassis and and fixed it upright and pooped the grill back in.
pcb manufacturing and assembly