ok, i was planning on converting mine to fill up tires, from say 10psi to 25 psi. also maybe to run a trian locomotive horn and prolly not, but run small air tools. i guess i can try it and see..btw, i was looking for AT LEAST 60psi...did all cadillacs have air suspention?
No, ALL Cadillacs do NOT have air suspension. Your idea about airing up tires is fine. GM used has used the system for just that on several cars over the years. My '89 Bonneville SSE had a service port in the trunk and the car came with a hose and integrated pressure gauge for blowing up tires etc.
As for powering air tools, I'd doubt it since the minimum CFM rating for virtually any air tool is far above the on-board compressors capability.