On the top of the tranny there is a sensor. On the type R you will have to remove the Air intake and look on top of the tranny you can't miss it. It's the only sensor in that area. It has 3 10mm bolts securing it. It comes off in two pieces You must remove the top piece (It's Plastic with a connector attched to it. then you can get to the other two 10mm bolts. Becareful there is a small pin inside that can fall out if you turn it upside down. This has a rubber gasket on it so it fits kinda snug. I hope this helps.
As for Lucas
http://www.lucasoil.com/Product_Deta...m?Product_ID=8 I'm sorry it is called Heavy Duty Oil Stabalizer.
Key Benefits
Increase oil life at least 50% longer
Reduces oil consumption
Eliminates dry starts
Raises oil pressure
Increases power and miles per gallon
and the Transmission additive
http://www.lucasoil.com/Product_Deta...?Product_ID=12
It's called Transmission FIX but it can be used as a preventive maintainance measure as well. There are lots of other Lucas Products on their site but the only ones I have experience using are the oil Stabalizer, Transmission Fix and Injector Cleaner.