The combination of a Nissan Micra and a Lotus Excel to make a rally car at first comes across as a bit bizarre. This combines the bug eyed looking body of a K12 generation Nissan Micra with the updated mechanical bits from a Lotus Excel.
The engine is a modified Lotus 912 unit from the Excel stroked to 2498cc resulting in 270+hp. The gearbox is the stock Toyota unit as used in the Excel. With Lotus and Toyota collaborating in late 70s and early 80s there are a few other Toyota bits like the rear axle.
Unfortunately for them the rules changed so they were no longer able to race it and instead built an older Sunbeam.
Check out the full specification at: Lotus Bits