Tifa......the Clifford alarms available through Best Buy are basically rebadged DEI units. They are of the same quality as thei Viper, Python and Sidewinder counterparts. DEI products are made well, relatively easy to install and have some nice features. Unfortunately, most large chain stores that carry them (Best Buy, Circuit City, etc.) do not spend the necessary time in performing a quality install. They want to get your car in and out of their install bay as quickly as possible. Check some of your local small shops and check the credentials of the installers. Ask to see a job in progress or samples of their work. Most top installers keep pictures of their work. Things to ask/look for are:

Brain placement (should not be easily accessible)
Integration of wires (should look like factory wires)
Placement of siren (should be out of sight)
Placement of sensors (shock and motion)
Valet switch placement (should not be in plain view, except for Clifford G4 models)

If you want a step-up in a system look at the older G4 Clifford models (AvantGuard 4, Millennia, various IntelliGuard models). These units were designed and built by Clifford before they were bought by DEI. They have by far the best security features of any alarm system.

BTW.....what area do you live in? I might be able to recommend some shops to visit.