steering wheel shakes while car is on highway. I also smell antifreeze.

Does it shake worse on the Southern State Parkway or on Grand Ave.? --Have tires checked and rims, possibly a bent rim or bad tire from hitting a pothole. Coolant smell should be checked ASAP , those engines don't tolerate overheating to well. Ask around for references to a good shop!

Shaking could also be a wheel balancing issue. Since you mention the highway, I assume you're driving at a speed of 50mph or higher. If this is when you feel the shaking, have the balancing checked on your front tires. To be save have all four done. Should cost about $15 per wheel. Definitely have the coolant levels checked, and have your vehicle checked to make sure there are no leaks.