There is only one good answer on this one, a junkyard. Since these were economy cars, and are now almost 20 years old, I dont think you will find any after market parts for this kinda stuff. Getting these parts from Florida, Texas, or Washington state, or Colorado is HIGHLY recomended. Rust is usually not a problem in these regions
Looking in my factory service manual for a 1989 Chevy Celebrity I found no reference to an accessory relay.
I don't know what the thing you speak of is, it doesn't sound like something either of my 1988 Chevy Celebrities have. I would suggest that you go to a wrecking yard and see if you can find your replacement there. It doesn't have to be from a Eurosport as long as it is the same engine.
If it is a sedan or station wagon you can probably find the door in a wrecking yard, If it is a coupe those doors do show up in wrecking yards but not as commonly.
Looking in my 1989 Chevy Celebrity manual I find a park relay inside the wiper motor but no reference to an external wiper relay. There is a fuse on the fuse block.
On some cars there is a sticker in the engine compartment with a belt diagram.
You can find fuse block diagrams for your 1989 Chevy Celebrity in either a factory service manual, Chilton manual or Haynes manual. If you don't have a manual your local library may have a Chilton or Haynes.
There are several Eurosport retail stores in the UK. Below is a list of a few of these stores: Euro M-Sport at 5 Mullydoo Rd, Mountfield, Omagh Eurosport Exhausts at 6 St Albans Rd, St Annes Europa Specialist Spares at Fauld Industrial Park, Staffordshire
autozone has search that helps locate anything on your car. good luck
Prices tend to vary with suppliers, there does not seem to be a standard price. When I need parts for my Chevy Celebrity I survey the local sources and buy the best deal I find.
Why are you a celebrity?Oh my God your a celebrity!
The transmission fill is through the tube the dipstick comes out of. You will find the dipstick near the firewall.
Wikki Feet ,The MousePad. Celebrity feet and Soles. Just Google Celebrity feet.