I am thinking about getting working on my car for jobs such as changing coilovers and the exhaust. Since I don't have a compresser, I was thinking about getting a cordless impact such the Ingersoll-Rand 2530K:

LINK

What do you guys think about cordless vs. air impact. I have never used an impact gun before so your opinions will be greatly appreciated.

 

I purchased a cordless impact before and returned it. It did the job, but think of all the other cool air tools you can have when you have a compressor.

 

a cordless impact is a great tool to have. for times your hose can not reach. working in a shop; your air hose only goes so far. then you need to hook up an extension.
for interior work this is much cleaner to work with. no dirty hose in the car. more angle etc.. just know your tq settings and drill/driver .

just completely read your post; for the work you are going to do air is better. but not needed.
at work i usually run things down the the cordless and then torque the bolts down. like under bodysupport frame,wheels etc.

brakes,shocks i use air.

 

I-R typically makes good stuff, but I don't have much experience with their tools. I have had experience with the CT3850 from Snap On and I think its great:

http://buy1.snapon.com/catalog/item....group_ID=16217

 

An electric impact is never going to be as strong as an air impact.

But, for the average user, an electric impact will work fine, and probably be alot cheaper than an air one, as far as total cost involved. For the tasks you have listed, that impact should work fine.