This was a question asked on the STF I'll post my answer here,hope this answers some general questions.
Anyone else who's done this feel free to add or discuss what
they have done.
Things needed to install a Rotary engine in a '72 Super Beatle=
2-Rotary Engine Automatic Tranny counterweight
3-Kennedy Adapter(flywheel,trans adapter)
4-VW Clutch=throwout bearing,disc,press plate
5-6 Volt VW starter
6-6 Volt starter bushing
7-Bolts and nuts for Mazda flywheel,VW clutch,
8-VW engine to tranny nuts and bolts
9-Crossmember for front mount on Rotary engine==(I used steel tube welded to Mazda
front mount and all-thread hooked to the bumper brackets)
10-Custom exhaust piping and muffler(flange from Mazdatrix and stainless exhaust pipe,Magnaflow muffler(must use stainless tubing due to high(2000 degrees) exhaust temp.Mufflers and routing your choice.Mine curves under the tranny and comes out under right rear fender.
11-Custom piping for water to and from radiator(muffler shop ran mine)
12-Hoses from radiator and engine to water pipes
13-Radiator(I used a Mazda 3-row radiator from a RX-7 that had a Auto tranny)mounted in the front with vent where super beatle louvers used to be.
14-Fabricate throttle linkage(I used Mazda
throttle cable spliced to VW cable and small
L-shaped bracket to hold cable.
15-Wiring -from VW to Mazda(Use two manuals-VW and Mazda and just hook it up ,LOL)
16-Gas line hookup(Mazda style carbs use a return line-I used stock VW gas line for return and ran new 5/16 steel gas tubing under car along pan bolts-schools out on need for return line-you decide)
17-Optional at extra cost=Modified carbs,special muffler,MSD ignition,Turbos,fuel injection,etc=how much money you want to spend ?
18-Transmission=I used the stock tranny,cause its what I had.Choices are many-
Type 1 bug,Type 2 bus,Porche etc.
19=Oil cooler(Rotaries must use a oil cooler,I used the stock early style cooler with the stock hoses,mounted the cooler on the rear panel below the engine cover with a small fan blowing thru it..Your choice on what cooler and where to mount.
20-Do research on Rotaries,forums,web sites,etc.Lots of info out there.