On my 3 previous VW Jettas use of a floor jack had caused at least one mutilated jacking point on each Jetta. Make a "jacking pad" from a 4" piece of 3 X 1 1/2 channel iron and a 4" piece of pine 2X3. Trim the sides of the pine to fit the channel, then glue the pine into the channel iron and cut (safely) a 3/8 X 1 1/4 groove in the pine. Make 2 if you use 2 floor jacks...use jack stands if you are working under the vehicle. Work safely !! Carry one in your trunk if you are using a Wally-World scissors jack.