Check with the dealer but also read the vehicle code to determine the percent of light that must be visible. Standard taillights need to be seen from 1000' to the rear for cars newer than 1978.
In California, it is not a good idea. Anything special gives the cops probable cause to stop you and most CHP officers will use this to stop and cite.
Feel free to contact us for a consultation. Iannelli & Associates, 949 729-3171 This answer does not constitute legal advice and no attorney client relationship is created. Every case has many facts which are different and distinctly theirs, make sure that you understand this is general information and it would be advisable to constact a competent lawyer for personal legal advice.