I have a roadster with 35000 mile on it, no top problems, no ignition fix, and I drag race, drive hard, and am on my 2nd set of tires. So, no, these aren't common problems but are problems of a car that wasn't taken care of. Alignment comes to mind on your tire problems. Running proper air pressure would be next. The ignition does seem to be a problem for most. I have my theory on that, but I will keep my mouth shut, and the top, well, we need to know exactly what it isn't doing....we will help if we can.