If you tow an auto without the engine running there is no oil getting to the back "half" of the gearbox. therefore you can damage the gearbox bearings, meaning it'll need to come out and rebuild it!! If you have to tow it then remove the propshaft to avoid this, although it can be a bit of a fiddle to get it out on 300ZX's. It won't be legal to tow it if it hasn't got TAX, MOT or Insurance. The police can (and probably will impound it!). You will have to move it on a trailer, unless you drive it to a pre arranged MOT. I'm an MOT tester, and have towed a lot of cars over hte years, the above is how the law stands!! Hope this helps ( and you don't get your car impounded!!)