New Owner

Good Morning.
I just purchased a MR2 Targa Top i was told it is 1991 but the registration papers say 1990.
As i do not know anything about this car can anyone help me with a few problems the brakes shudder and are not very good and between 100kmh to 140kmh the steering wheel shakes and vibrates badly.
Are there any on going problems with this model.
Thanks
Dave

I had a similar thing with my rego/build date.  I was told it was a 91, the rego papers said 91.  Not long after I got it, I'd gone to buy something & was asked "is it early 91 or late 91" because apparently that made a difference.  When I had a look & found the build plate, it was actually August 90.  I remember one website not even having 90 as an available option. (I think one of the CTP websites).

G'day Dave, and welcome to the MR2 community.
 
Steering wheel shake at constant speed:
Maybe first of all have the wheels properly balanced, as well as checking the front wheel bearings, ball joints, and track rod ends for any play/slack.
 
If you have aftermarket wheels, they may need concentric hub rings to center the wheels properly. Tight fitting metal ones are best.
When fitting mag wheels, to ensure even wheel clamping the wheel nuts should only be tightened using the so called ‘star’ pattern, first in a couple of passes, then finally tightening with an accurate torque wrench. (I use 80 ft/lbs) 
 
Hub runout: 
Assuming all the above items have been taken care of and you still have steering wheel shake, the next thing to do would be to check the front hubs for excessive runout that may have happened after a front end collision or a wheel hitting the curb at some stage. That could cause the hub/rotor/wheel rotating assembly to be out of balance.  
 
Steering wheel shake that only happens during braking is probably caused by unevenly worn rotors.
 
 

+1 for a read of http://www.mr2australia.com/mr2play/tm.aspx?m=70521&high=oversteer
Very important info for people new to MR2's.
 

High idle:
Did you disconnect the battery?
If so, the ECU looses it's settings.
When you reconnect it, I find on my car the idle speed will be high, but it corrects itself after a few km when the CPU 're-learns' the settings.

No i did not touch the battery.When i got the car it idled on 1500 the previous owner said just hit the accelerator and it will idle properly but this did not happen it seemed to fix itself. It now idles on around 800 but if the weather is a bit colder it will idle on a thousand i wonder what will happen in winter that is why i am trying now to find out what is going on.

Welcome, dave.
Higher idle on cold is normal, but it should settle as the engine warms up. If the engine is staying cold, the thermostat may have been removed/bypassed.

You can get a high idle if your coolant system has a leek or has not had the air bleed out correctly as it creates an air lock around the idle control sensor which send the wrong signal to ECU. The ECU think the engine is running cooler, it gets more fuel, which gives higher revs at idle.