Disgusting unsafe cars

Lately the standard of Uber cars it's dropping, from last five trips I've kept quite and I think it's about time to tell the truth as it is, for an international company to send us such dirty, not road worthy and unsafe cars really frustrates, it seems as if Uber is now just accepting any car that comes in without even cheking if it's suitable for business or to drive customers. I honestly traveled with fear and concern of lately, Uber standard is dropped and it's so not good and safe.