I carry a spare under the hatch of my z4 coupe. I can tell you from experience that inflation kits don't work too good when you blow the sidewall out of the tire, and who wants to fool with a kit that is going to coat the inside of your tire with a lot of goo?

But what to use for a jack? KYB in Japan makes a lightweight rally jack but no-one in North America seems to have it in stock, and most of the auto supply jacks are pretty heavy. Any suggestions for a good quality liteweight jack to pack around in the trunk?

I don't carry one with me, but having had occasion to use the standard BMW jack from my 3 series, I found the thing actually worked pretty well. You could likely find one on Ebay, or even cheaper rummaging around a junk yard. Or there's always the dealer...

Thanks for the suggestion Treepusher. I've done some research on the web and I think the jack and the spacesaver spare out of a 2003 or 2004 330xi will likely get the job done. Will have to put a spacer, likely about 12mm, behind the spacesaver spare to get clearance and use longer lug bolts to get the job done. Will likely weld a half inch drive socket on the jack and spin it up with a cordless impact wrench. Will carry a breaker bar for backup.

If you really wreck your tire, that inflation kit is no help at all and you can find yourself in a bad situation. The cavalry might not be coming over the hill.

If you really wreck your tire, that inflation kit is no help at all and you can find yourself in a bad situation. The cavalry might not be coming over the hill.

Agreed. Road debris took out both tire and rim on my old car a couple of years ago (full blowout at 85, big fun). Anyway, without a space saver spare I'd have been SOL.