Wont go over 30 without shaking - 2003 Hyundai Accent

Try balancing tires.

ignition fault check replace spark plugs leads test it then coil packs

Put your spare tire on one side of the front. Drive it, if it does not help, replace the spare and then try removing the other front tire. Drive it and see if it helped.

The tire that caused the vibration probably threw a weight or has a broken belt. Have that tire checked and repaired, then have the Tire shop put the spare back in the trunk.

If it is not a tire problem check your tierod ends. They connect both front wheels and if there is a lot of play, you can get shake and wobble from the slack in the frontend.

Sometimes front Rotors can cause a shake when you hit the brakes. If the car shakes without pressing the brakes, then its the tires or frontend.

if your check engine light is on find a part store that will do a free code scan it sounds like a coil pack but its hard to determine without more info if your mileage is high when was the last time plugs were changed

is it a 4x4? check the front u joints.

I would try to replace your spark plugs, and spark plug wires, My 88 Vic did the same thing...now it runs like a champ....you could also try fuel injector cleaner.

it could be a motor mount check the condition of it or it can be that something with the suspension might need attention . . those things can cause vibration at certain speeds

i have same issue

car shakes at 30 is proberly front rotors