There are many people who have tried the IRS on MK2's, DJM built the famous Colin Mcrae car

http://www.djm-motorsport.co.uk/mkii_escort_mcrae.html


Phil Collins sucessfully campaigns a similar car in the English and Irish tarmac championships...







And some others that are or have been built...

Dave Thwaites car is on IRS...



and this car currently being built....



They all use a similar concept of an Escort WRC cradle and Esc WRC uprights/hubs...

Too expensive on most people's budget and as has been said above seems to have little competitive advantage over the live setup, Simon Mauger and the Irish mk2 boys are still achieving as quick stage times...

The use of an IRS does allow for more suspension travel and a superior suspension unit to be used, larger wheels can be accommodated, wider track is possible...

I pal of mine is putting a nissan back end into a sunbeam...again fairly straight forward to do but he only doing the conversion to get away from the rubbish sunbeam axle.....

It's a topic I have considered many times and I still can't decide which is best, both live and IRS have disadvantages and advantages.....