I have a 2009 Elantra with a suspension noise that seems centered at the drivers feet. They have replaced the strut & strut mount, the ball joint, the sway bar bushings all to no avail. It seems like everything is tight but the car continues to rattle when I hit bumps. Any ideas?

check the ball joints

if it has strut suspension, check for a failed bearing in the guard at the top of the strut
check for loose /worn rubber mounts on the stabilizer bar to chassis

indicates that the insulation rubbers around the subframe bolts are failed and the subframe is hitting on the cabin floor or the cabin floor in taht area is rusted out

Check ball joints

What you have is either a strut noise, or a ball joint noise. If the ball joint is bad, then that is your culprit, and if it is not then I would change the strut.

Have you have the ball-joints checked?

either the strut is not tight or the strut mount it bad. did you change the strut mount when you changed the strut?

front stuts need replacement, buy this point it would be both. you can tell most of the time buy if you hit a pot hole on the left and it makes a nosie thats the side. but after a few days of driving like this both are in bad shape and need replacement.

there is no bearing its just the strut, you can tell buy getting a jack stand and lifting the front and moving the tire side to side and back to front. usaly anything over 10-20 thouthands of an inch is bad, and that mean if you feel it it's bad.

but anyways to replace it you will need a sop, you have to compress your front srping in order to remove and install a strut.

Upper strut mounts aren't prone to rattling or knocking as they are usually under load all the time. Very few cars do not have a swivel bearing - a few old Fords are all I can think of. Most current models have the swivel bearing integrated into the strut mount, the main job of which is to insulate road noise from the body. Some cars use a swivel bearing fitted between the strut and lower spring cup.

Worn shock absorber internal valves can be very noisy over small bumps and road undulations and wear in steering rack components can make similar noises especially the rack slipper bearing, the rack end support bearing and the rack end joints.

Many track control arm ball joints have an internal spring to compensate for small amounts of wear. When such a joint has worn significantly it is not always possible to detect free play with hand pressure but they are liable to make noise on the road.

Struts that are housings fitted with shock absorber cartridges retained by a single large nut - the nut can sometimes be loose by a small amount causing the cartridge to knock inside the casing.

The strut piston rod and bush is subject to a great deal of force from the reaction of acceleration and braking and considerable wear can take place between the rod and it's bush. The trouble is any free play cannot be detected when the vehicle is jacked and the wheels clear of the ground and similarly cannot be detected with normal force when the vehicle weight is on the ground. I find lifting the car until the suspension is only compressed an inch or two gives the best chance of detecting wear though considerable strength and energy is still needed.

Okay....here is the steps first....and then the directions on how to use the tools:

1. Raise and properly support the vehicle.
2. Remove the front wheel.
3. Detach the shock absorber lower mount by removing the two bolts.
4. Remove the retainer nut, retainer, cushion and shock absorber.
5. Detach the cushion retainer from the shock absorber.
6. Compress the coil spring with a commercially available spring compressor.
7. Detach the stabilizer bar.
8. Support the upper suspension arm and steering knuckle securely.
9. Remove the cotter pin.
10. Loosen and remove the nut.
11. Using a ball joint removal tool, detach the lower ball joint from the lower control arm.
12. Loosen the suspension arm set bolt.
13. Remove the suspension arm set bolt nut.
14. Remove the nut from the strut bar front set bolt.
15. Pull out both set bolts.
16. Remove the lower suspension arm and coil spring. To install:
    
17. Installation is the reverse of removal. Note the following torque specifications:
    1. Strut bar front set bolt: 221 ft. lbs. (300 Nm)
    2. Lower suspension arm set bolt: 148 ft. lbs. (200 Nm)
    3. Lower ball joint nut: 80 ft. lbs. (110 Nm)
    4. Lug nuts: 83 ft. lbs. (110 Nm).