You may want to go to www.ada.gov to read the current law and there is a Q&A that's also helpful. I believe your asking for a designated handicapped parking place would be considered a reasonable accommodation (RA) under ADA. Keep up the documentation. While it's against the law to take retribution, we all know there is alway's a way for employer's to find a way to fire someone, but they do need to make sure it's for a documentable valid reason or they'll find they're having to explain to the EEOC if there is any reason to think it's related to requesting a RA.