General Maintenance & Repairs - Please help 99 formula

Hello

I have a 99 formula with 87k on it and sometimes when I drive it jerks at around 35 to 40 it doesn't do it all the time and I do not hear any sound when it does it. Not sure if I should have it looked at or not.

mine did kind of the same thing, turned out to be my tie rod ends, jack up the front end, grease up all the fittings and try moving your wheel left to right by hand.

is a A4 ? it mite be the converter lockup clutch not working correctly.