Hello. .i have discovered some rust damage on My BMW E39 at the rear of the sills where it meets arches plz see pic.. i was tempted to tackle it myself but then i thought i ll see if i can get a pro to do it . Unfortunately most welders dont seem to want to do a small patch, most want restoration work and big jobs, so i am again left with no option but to tackle it myself. I can put the car on axle stands high enough but i am not very familiar with upside down welding, certainly never has to spot weld underneath a car either. Any leads and advice very welcome.