Originally Posted by mleskovar
Given the choice always use internal patches over plugs but patches won't work at all close to the side walls because of flexing. The "hole" is only as big as YOU make it (unless the FOD makes it too big for even a plug). Once you get the tire goo into your tire pressure sensor and tire air valve they are history and need to be replaced. The goo/sealant makes a mess and is not easy to remove. If left in the tire it can solidify or freeze and cause tire balance problems. Ask your tyre supplier what they think of the sealant. But to each his own.
+1. Yup, when BMW assist came for me when I had a flat on the "other side" of Germany... he also said it is always better to use a spare tire(even a mini like I had in the trunk) then to use the Mobility Kit. It is a last resort.
I also believe in order to "put" the glue/sealant in the tire... you have to remove the valve stem "guts" with a tool. The service tech also said even with the sealant inside... the wheel WILL vibrate like crazy. So I installed my mini donut. No vibrations, but major handling issues and the rear end was always "wagging" going down the road. Not fun.
That is why I bought a full size spare. Never again. I don't care how much trunk space I lost. I feel safer with that full size spare back there!