A rolling start?
 

My starter won't engage and I'd like to get my Series 3 to the mechanics. Assuming I can gather enough willing friends to push her out of the slightly uphill garage and get her to the downhill side of where I live, can she start with a rolling start kind of like we used to do with a manual tranny? Anyone???

I don't think you'll be able to do this with an automatic, sad to say. I'd recommend a flat bed tow.

I've done a rolling start with a Jeep automatic. I've got a pretty good hill here so should get something up to 30 mph. But if it doesn't then I'm stranded.

That will only work if your automatic transmission has a rear pump. If it doesn't, you can push it all day 100 mph and it won't move the engine.
(';')

also my 1986 XJ6 handbook says emergency starting cannot be undertaken by towing or pushing.