Q: Car vibration when stopped or moving slowly

Hello. Most vibrations are related to some kind of misfire. A misfire can be related to air, fuel, or spark. This vibration is noticeable when the vehicle is not moving because the RPMs are lower. As the vehicle speeds up, there are more cycles and a misfire gets drowned out. You may want to start by having the vehicle scanned for diagnostic troubleshooting codes. If the computer is detecting the misfire, it will give you detailed information on which cylinder is at fault and what about it is failing. With how old the vehicle is, spark plugs are likely to be giving you issues. If replacing them, replace all of them at the same time. Do some further inspecting, and have the vehicle scanned. It is likely you are having a misfire.