Haha yeh that's for the radio mate, the 2 small lines running thru the centre of your windshield are the antenna receivers. It also registers FM, for me anyways. You can get an adapter at an electronics store. Reception is actually ok but may struggle in heavy traffic
Anyways you wanna look for this fella:

Mine snapped recently where the front (1) cable connects to the rear cable (2). You'll have to pull off the undertray towards the mid-rear section of the car see it. It's a 2 cm thick cable with foam padding. Then I just followed this lol
http://www.stephenmason.com/cars/mr2speedo.html Anyways you unscrew the connector and there's a pin sticking out like he says in first paragraph, test it with your drill to see if the speedo needle works. Otherwise it could be the actual speedo gear (3). You'll have to take out the air box to have better access over the engine bay.