How to extend your motorcycle engine life

bad transmission seals, the new formulation of gasoline eats through seals, especially if the bike has sat for any extended period of time.

I believe the 3.2 is a Honda/Acura engine and not a Isuzu engine. Are you talking about changing the engine oil or the transmission fluid? I ask because you state "the oil drainage plug" but later you mention the Automatic transmission.
As for engine oil plugs, they are almost always found low on the engine oil pan, sometimes facing the front (like my Jag), to the side (like my Ford Ranger) or to the rear like my 90 Acura Legend 2.7L V6 did. Most have a bolt with a washer that should be replaced every time. If it doesn't look like a large hexagonal bolt head it could very well be a rubber plug that is pushed in. Not a good design in my humble opinion. If you change the oil be careful not to do it when the engine is hot as the oil is also quite hot. I believe in doing it when just warm, more drains out. I find it beneficial to drain about a quart out, put the drain plug back in and add a quart of Gunk or Snap engine oil slush, start it (but don't rev the engine & DO NOT DRIVE THE VEHICLE) and let it just idle for 15 minutes. Give it some time to cool then remove the drain plug and let it drain out. Next remove the oil filter. Always ALWAYS pour fresh oil into the new filter a couple of times before screwing it on, and spread a little oil on the little rubber gasket on the filter first. I recommend synthetic oil for any vehicle as it doesn't break down into coke (hard rock-like black stuff) like conventional oil does. Those coke deposits are engine killers. I like Mobile 1 extended fuel economy. Synthetic costs more but lasts longer. If using synthetic were to only extend the life of your engine by two or three years, I consider it well worth the added expense. It should reduce wear in the engine, keep it much cleaner, make it quieter, and give you better mileage because it's slicker (less internal friction).

you can do it both ways. . .

No,

Section 03-03: Engine Cooling 1997 Taurus, Sable Workshop Manual
REMOVAL AND INSTALLATION Radiator Aluminum Core, Crossflow
SPECIAL SERVICE TOOL(S) REQUIRED Description Tool Number Fuel Line Disconnect Tool Set T90T-9550-S
Removal
CAUTION: Do not mix Standard (green) Coolant with Extended Life Coolant (orange). If mixing occurs, drain engine cooling system and refill with originally equipped coolant type. If this contamination occurs, the service interval of Extended Life Coolant will be reduced from 6 years/150,000 miles to 3 years/30,000 miles.

1. Disconnect battery ground cable (14301).
   

1. Remove battery (10653) as described in Section 14-01 .
   

1. Remove clip retaining contant control relay module and position module aside.
   

1. Remove battery tray (10732) as described in Section 14-01 .
   

1. Remove radiator cap (8100).
   

1. Raise vehicle on hoist as described in Section 00-02 .
   

1. Remove radiator splash shield.
   

1. Drain engine cooling system as described in this section.
   

1. Remove the radiator mounting bracket assembly.
   

1. Remove lower radiator hose (8286).
   

1. Partially lower vehicle.
   

1. Remove upper radiator hose (8260).
   

1. Remove radiator overflow hose (8075).
   

1. Remove upper A/C condenser core retaining bolts.
   

1. Remove upper transmission oil cooler tube clips.
   

1. Remove lower transmission oil cooler tube (7C410)(EPN=7C410)using 3/8 Inch Fuel Line Disconnect Tool T90T-9550-C.
   

1. Raise vehicle on hoist.
   

1. Remove lower transmission oil cooler tube clips.
   

1. Remove lower transmission oil cooler tube (7C410)(EPN=7C410)using 3/8 Inch Fuel Line Disconnect Tool T90T-9550-C.
   

1. Remove transmission oil cooler bracket and position transmission oil cooler aside.
   

1. Remove lower A/C condenser core bolts and position A/C condenser core (19712)aside.
   

1. Remove radiator support bracket.
   

1. Remove radiator (8005).
   

Your motorcycle comes from Honda usually with 10w-40 mineral base motorcycle oil. You can use any oil that is JASO MA certified motorcycle oil. 10w-40 for cold climate. 20w-50 for warm climate/touring. Car oils use different additives and may cause scoring in certain types of cam bearings. Do not use any oil that says " Energy Conserving " on the label . It will shorten the life of your wet clutch and transmission gears. If you choose Synthetic oils, they will help your bike run cooler and shift easier. At 1300 km you should have no problem switching over to full synthetic motor oil.