They super smoked taillights look really good IMO but some people go way too dark, I have almost rear ended the guy dating my gf's sister in his mustang because his brake lights barely show through the tint.
i got the headlight tint from ebay worked out great but make sure u get off all the cleaning stuff cause it will bubble up then u can tint as dark as u want or as light as u want. i think its $16
heres an idea. say you had a silver truck. would you think it would work if you were to mix the silver into some clear and paint the light that way. would it blend in well?