I don't know how many of us would like to have a switch disabling the passenger side airbag on your del Sol, but I know I've been at a loss when my sisters kids want to ride with me. They are too little to ride with the airbag enabled. If you have a similar situation, here's how to go about getting a switch installed:
 

1. Go to http://www.safercar.gov/airbags/brochure/ and read the brochure.
 

2. If you have questions contact Peter Ong at the NHTSA's Airbag division: 202-366-0583
 

3. Then visit http://www.safercar.gov/airbags/brochure/switchrequest.pdf to download the application.
 

4. Complete the form and mail or fax it in to the address/phone number on the form. It usually takes 48 hours for them to process and return to you a permit to have the work done.
 

5. Take the permit to your dealership or repair facility to have the switch installed.
 
Some dealerships may not want to do the install even with the appropriate paperwork filed. You can try to press them but liability issues may mean they will deny the request. In such a case try other repair facilities.