On the topic of leaving e85 in the car for a long period of time is a subjective one. Plastic tanks are fine, steel ones gather a tiny bit of surface rust. E85 has a habit when you first switch over to 'clean' out your fuel system, so a fuel filter change a short period after making the switch is recommended.

Australian ethanol has a substancial additove package in it, so it is nowhere near as corrosive as american ethanol is by all reports. Metal fuel lines cope fine, aluminium copes fine, some people recommend annodised though.

Fuel filtering materials can be reactive. I have seen some paper elements have a moss type slime build up on them when sitting for periods of time, but they have been old filters before ethanol was introduced to the system. Synthetic media is fine, as is stainless steel.

Oem fuel lines cope quite fine, i have seem some issues with aftermarket fuel hose from codan and goss, but is usually after the outer case of rubber has been exposed to e85 and air. Either way, you are after SAE30R9 hose (standard efi hose is SAE30R7) or just get proflow 400 series or aeroflow.

The main thing i have experienced issues with ethanol cars and storage is injectors and oil/engine internals. Standard injectors use a ferrous metal for the ball and seat (usually iron). It is very common for long storage injectors (6 months onwards) to stick, or have the seats pit, messing with the spray pattern. I have had more issues with race cars running drum ethanol (again due to additives packages), but have had several sets from pump ethanol as well. With the plethora of cheap, easily available injectors with full stainless internals nowdays, there is really no excuse, or like rob said, tun a tabk of pump fuel through the car before storing.

Oil can be a bit interesting. I had a racecar that had done wtac and 3 track days, been driven in and out of the shop for 2 weeks, then stored for 3 years. The oil was completely destroyed and broken down, and a thick jelly found in the oil. Water and ethanol retention in the oil can cause some gumming up and corrosion/rust issues with engine internals.

Long term storage comes down to some common sense stuff. Store cars with full tanks of fuel, so there is no air to react with. Fuel systems that seal correctly will not be affected the same as ones that don't (cars with deleted carcoal canisters and rhe hoses left open suffer worse)

Another thing to be considerate of is oil selection. Some oils are more tolerant of E85 than others. Full Ester PAO oils (motul 300v and a few others) dont mix with the moisture and some other e85 byproducts, which is fine in race cars and cars that have the oil frequently changed, but not suitable in street cars. Type 4 synthetic oils generally work well, vompared to the hydrocracked type 3s. Most oil manufacturers list their e85 compatibility (penrite ten tenths, motul ester sport, liqui moly gt1 etc) also methanol rated oils are good options (brad penn etc)

Also i read in your other post about tossing up between the fueltech ft500 and the adaptronic.

With the fueltech, just suss out how many people can actually tune them. They are also a pretty drag racing focused ecu, and im not sure about their flex fuel capabilities, or compatibilities trying to use one on an mr2. There will be very few people that will be able to help with troubleshooting etc and tuning with such and ecu.

Adaptronic has a pretty good support base, both from the manufacturer and their staff, forums and various online resources and even forum members (robk not only has one on his car, but also worked for them for a period of time, so is fairly familiar with their product)

I am employed by a motec dealer and haltech dealer, so i am fairly familiar with their products (motec from m8 till m1, and haltech id rather not know about anything pre platinum)

The thing i can never stress enough to people is how you go about choosing an ecu. If your paying for tuning, find some shops whos work you like, and find out what they recommend. You could have the best evu in the world, but if nobody can tune it, use it or get the most out of it, whats the point? If you are going to tune your self, how much support is out there? How easy is the software to navigate? Finally, what features do you actually need? Why buy a 1300 dollar ecu that does quad cam vvti, nitrous control, and 65 million other features you will never use (and does none of those or the basics well) when for the same money you can buy a more basic ecu that will do what you need from a better manufacturer.

Thanks guys, really appreciate all the info.
 
I'm still weighing up the options but it is all very interesting.
 
As for the ECU, the Fueltech looks great but honestly probably wont be what happens, the turner I've been pointed to seems to like Adaptronic's.