If mass is a measure of inertia, does that mean if an object increases in mass as it is in motion?

Question

Mass is a measure of inertia, right? A car traveling at a high speed has a lot of inertia. Does this mean that the faster the car goes, the greater the inertia and the greater the mass?

Answer 1

No:
Inertia as energy is MxV.
The increase comes from the speed, not the mass.
(Until you get to relativistic speeds that is.)

Inertia as a property is resistance to acceleration.
It doesn't change. (Again, until you get ....).

You are confusing the terms.

Answer 2

Yes.