You are using the wrong point spread functions for your debluring algorithm (pillbox is a bad choice). For best results filter with a median filter to remove the S&P noise and then deblur with a gaussian kernal. I would skip the motion deblur as the image doesn't seem to have strongly directional blur. You will need to play with the sigma of the sharpening filter to get the best results.
img = imread('car_plate.jpg')
subplot(331);
imshow(img), title('Original Image')
blur = medfilt2(img,[3 3]);
subplot(332);imshow(blur);title('Filter image');
deblurSigma = 10; %Adjust this to get the most visually pleasing results
motion_noise = fspecial('gaussian', 15,deblurSigma);
luc1 = deconvlucy(img,motion_noise);
subplot(333); imshow(luc1);
title('Disk and Lucy');