Lots of play in steering at 80mph
 

Hey guys! I've owned my '98 Boxster for about a year now and since day one I've had a problem with the steering once I get up around 80mph. There's about 1-2 inches of play in the steering which makes it feel very dangerous. What would cause that?

Play, or shake ?
If you have play, you would have it at any speed and even on a stop.
Now if the steering wheel shakes, it's most likely your tires that are out of balance or out of round.
It can also be bad shocks, or worn suspension parts.

Is your spoiler deploying? It should deploy at 75 mph and if not the front of the car can get light and cause a loose feel in the steering.

Does the feeling remain or increase/decrease at even higher speeds?

As the spoiler is at the rear doesn't it create rear downforce that will make the front of the car lighter? Or am I missing something here!

How many miles on the car?

Have the front-end suspension bits ever been rebuilt? When was it last aligned?

Time to check tie rod ends, ball joints and bushings

Since the spoiler is not a wing it does not per say create down force, but disrupts the airflow over the car and prevents upforce.

The shape of the car is basicially a wing and without the spoiler, it would want to lift at higher speeds. The front would start to lift first.

There is a thread started by Kram about changing the speed where the spoiler deploys where this is discussed in detail

If it tightens up at speed (under down force) then lower control arms, or lower ball joints?

steering
 

Tie rod ends and lower control arms really tighten up steering. If they are in good shape maybe just an alignment will solve problem.

get all your wheels balanced/checked if they are balanced. Also check that the alignment is correct, when checking the alignment inspect all the mechanical parts mentioned already for wear.