I have an audi 80 2.6v6. it blows fluid from expansion chamber

I'm assuming for now that these are two separate problems:
1. Overheating and emptying expansion tank.
2. Leak into front passenger footwell.

Solution to 1. is likely to be a crack in the expansion tank. This happens often with these tanks. Look under the cap and you'll find two necks. The narrow one is the pressure tube that the lid seals in to. Check the narrow neck for any cracks and check the pressure cap o-ring for condition. Replace both if suspect. They're cheap from FCP Euro or ECS tuning.
The wider neck is the overflow. This drains into a small tube under the lid area of the tank. You could connect a hose to this if you were so inclined, but it normally it just drains into the engine bay (onto the left hand exhaust manifold normally on V6's!). If yours is losing the coolant from here its a classic sign of a cracked filler neck.
Make sure the cooling system gets bled properly as well - top bleeder is the right hand heater hose (factory hose if still on the car will have a hole marked by a white circle - pull the hose off the heater core connection tube to expose this hole to the coolant, undo and raise the expansion tank above the heater hose level to bleed).
On V6's the lower bleed is on the engine cross flow pipe on the rear of the engine on the opposite end to the engine temp sensor - 6mm allen key undoes from memory. Not sure where lower bleed is on 4 cyl models - possibly the coolant pipe in the vicinity of the inlet manifold.

The other possibility for 1. is a failed cylinder head gasket, but I'd be suspecting the expansion tnk ahead of this. Seek professional help if the expansion tank isn't the issue.

2. I would suggest is a blocked plenum chamber drain. You can check by pouring some water down the windscreen with the bonnet (hood) open and seeing if the plenum area fills up without draining or draining slowly. Main drain is in the middle I think and It gets clogged by leaves and debris. Cleaning is difficult, but you can try a shop vac with some heater hose taped to the nozzle to try and get in there, or some compressed air with an air gun or something to try and blow it through.
Search something like "Audi B5 plenum drains" on Google and you may find some other suggestions.
2. may also be blocked HVAC drains for the airconditioning...

You are correct to be concerned. Look and see if the transmission has any vacuum lines. If it does, check the lines by disconnecting them and see if transmission fluid is inside the lines. If there is transmission fluid present, the engine is drawing the fluid out of the transmission and burning it in the combustion chambers.

Radiator overflow- Check color of antifreeze in overflow tank. The radiator can have 2 chambers. If the chambers breach, the fluids can mix. Since the overflow can vent the excess fluids, it can provide an outlet for the trans fluid.
Leaks, most common. There should be staining and presence of oily residue. Check for lower cooling coil assembly. Some Makers use a separate cooling unit similar to a steering cooler if a 2 chamber radiator is not equipped.
You may be able to simply go to a quick change oil shop and drive over their service bay. They could check for leaks.

english or espanol los siento pero ?? no speakie italiano ,is it true italian tanks had one foreward and twelve reverse gears ??

Not sure if there are carbs on car or if it is direct injection. If carbs spray into float chamber(s) if injction I think you will have to spray into cylinders via holes for spark plugs. Pleae note have never used starter fluid on direc t injection my self so I am really not sure if that will work. I assume that you have checked that fuel is getting to engine. Hope this helps.

You have a leaking engine cylinder head gasket, coolant is entering the combustion chambers of the engine and being expelled out the tail pipe.

the radiator expansion tank is on the left as you look into the engine bay with a radiator cap on top(its an opaque plastic bottle).
the washer fluid is just a cap with a spray pattern on it.normally orange in colour but i have seen them blue.

have you tried to reset immobiliser/alarm system???

Power steering fluid level checking:
- vehicle stationary
- front wheels in straight ahead position
- engine at normal operating temperature
- remove cap with dipstick from expansion tank and wipe off
- reinstall cap with dipstick and remove again
- fluid level between "min" and "max" markings
- top off with G 002 000 hydraulic oil if necessary
Power steering system capacity is around 1 liter, but it is not necessary to periodic change the hydraulic oil!
If oil level has dropped to the "min" marking, check power steering system, including hoses and lines.
It is not enough simply to top off the hydraulic oil !!!

Most of the time a vehicle will take between 6-8 quartz of transmission fluid. Just keep checking as you fill, so you don't overfill it and blow a seal.

Your transmission is sealed and has no dipstick for a level check, all models of VW and Audi are this way, this started in the late 90's, why did they do this? VW/Audi don't want owners overfilling there transmission's, if the fluid is not at 95-113 Degrees Fahrenheit then you can overfill thinking the level is low and not taking expansion into account.