Cadillac Repair: 2000 Eldorado ETC Maintenance, maintenance records, coolant

Question
I bought one last year with no maintenance records on it with 69,900 miles on it. Since then I am about to hit 80,000 miles. I have had the oil changed 2 times but I am concerned about the transmission and coolant maybe needing to be changed. Everything is running great at this point and the car has no codes. The dealer replaced some kind of spark sensor when I got the car and thats it. What would be a good time to service tranny and coolant, also maybe a complete tune up with new plugs and wires.
Thanks for your help,
Dave

Answer
The plugs and wires are the cheapest to do, on that car it should be $100 at the most, the transmission tune up can vary from $60 on up, the coolant is said to be good for 150,000 miles, yea right. I flush my cooling system every 30,000 miles, but it can go for about 75,000 miles.