So it's pointless to compare car prices to inflation because they are part of the basis of the measure. Hence why they track closely.
Inflation is always the main contribution to price increase. It only makes sense to compare price raise above or below inflation if you want to unearth factors specific to any given product or industry.
Money supply always changes. But yes, inflation is possible without changing money supply, if for example economy shrinks or there's some process that reactivated dormant capital that people had just sitting around and not being used by the economy.
In the end it's always the same thing. More money than it should be. It's just that "should be" is very complex and "more money" only a little bit simpler.