Cat deterrent

I'm having a problem with the neighbourhood cats. We are surrounded by houses that have grass-free gardens, whereas mine has shrubs and lawn and the cats that live on either side of us are enjoying using it as a toilet. We have cats sleeping on and under our car, hiding in our bushes and weeing on the grass. While this is all fine and dandy, they are killing the grass and its looking more like a burnt out/not looked after lawn. I'm a bit house and garden proud and we spent quite a bit of our money on getting it nice so I'd like any suggestions on how to deter these friendly felines into weeing somewhere else (perhaps the grassy park directly across the road?!!!!!!)

Thank you!

The only thing that I've known to work is what my Grandad used to do - air rifle. Bit illegal though, and time-consuming :D (yes, I'm a cat lover!!!)

Umm cats though will usually dig a hole for their wee/poo though, so on the grass is a bit weird. To encourage them to move, maybe dig an area and fill it with sand for them?

there is this stuff you can get, ive seen it at the chemist (big warehouse type one not the small local ones) its in a yellow bottle i think, could be white, and its like gell crystals you water into the garden, not sure how it works, but i was looking at getting it to stop the dog digging the garden beds, it said it worked on cats aswell, if you wanted to discourage werre they went the toilet and dug. if i think of the name, ill get back to you.

There is a product called cat off (or something like that) I think it's citrus based. Pretty sure bunnings will have something like that or similar. Maybe spray a border around your property? Another idea is maybe call into a vets and ask ideas? sometimes they have advice. our local vet was really helpful in suggestions to keep the neighboyr's cats away from our chooks. We have the most grass out of our block and any one time we will have 5 cats in our yard. Today there were 2 dogs too lol. I only own one cat.

HTH

Orange peel is supposed to deter them (they don't like citrus), and a few other things but I cant remember them off the top of my head! maybe give your local council's animal ranger a call and ask them for some ideas. i know when I worked in local government we had a fact sheet that listed a heap of things for deterring cats. I don't know if any of them actually worked but it's worth a shot!

Thanks everyone for the replies! It's really weird because they don't seem to be digging in the grass area, but DH and I have both seen them. DH would go with the air rifle for sure Kaz, he isn't a fan of cats!! Must be something about my lawn as opposed to the park across the road...wish they'd realise they have grass galore over there! I'll get on the phone and get some tips, thanks everyone!

At the supermarket in the cleaning aisle, I will ask Nanna the name cause I can't for the life of me remember, reminds me of Chlorophyl (Fernile or something)... but anyway, they HATE it, won't go within yards of it. You can put it around (liquid) your fence line etc and they won't go near it.
Dogs apparently aren't phased at all lol

Anyway, it is at the supermarket in the cleaning aisle, usually up high.