Buy a wreck of a car for £100, get it towed & leave it on the drive. 
You had to take it to the next level, didn’t you? 
Try making a Bucket O Crete (© Zanx) as shown in this thread. I prefer the one on page 2 with the steel tube to the one in the first post.
http://www.therevcounter.co.uk/uk-motorbike-forum/28372-for-anyone-wondering-what-bucket-o-crete-looks-like.html
We did this for a customer with the same problem
I got a large stack and store bin put a layer wet concrete in the bottom added an old u lock with sever bits of scrap though it and toped up leaving just a loop out the concrete
Add a heavy chain and Lock u locks of you choice when you move it can be picked up but not easily
Funny thing is after a few days it had a neighbours bike chained to it as well in the communal car park 
Get a ground floor flat with a large front door, remove the carpet from the front room and hey presto ! Instant garage
haha great ideas… that’s exactly what I was thinking…
Hmmm ok will post back when I actually have a flat and hopefully someone can help me source the bits and bobs! 
Another idea - if you want it to look inconspicuous outside a flat - use a cheap plastic dustbin and punch the ulock/ o ring / whatever through the side… just make sure the dustmen don’t try and lift it…
Or you could decorate it to give it a bit of colour…
Concrete is definitely the way to go - weighs twice as much as water (2500kg/m3) so a reasonably small block is still heavy.
If you need to dispose of it afterwards, bear in mind that smashing up a solid block with an electric kango is going to be no fun.
Assuming you want the lump to be bigger than a man can carry then i would cast in a few sections that stick together somehow. I have some thoughts on a way it could be done so that it could be re-used/removed (my dayjob is senior engineer on major concrete works so coming up with this sort of stuff is not unusual) - drop me a PM when you’ve sorted the flat if you want any pointers.
We heard wedding bells too 
Shhhh don’t say such things! :pinch:
Monkimark, I’ll drop you a PM when I get it sorted (hopefully I agree tonight on the place).
Thanks for all your help everybody!!!
Someone I work for poked a metal tube through a wheelie bin that his chain fitted through then filled the bin with strengthening rods and cement. It doesn’t look out of place in front of his place and impossible to move.
Well went to see the flat today… put in an offer and waiting to see if the landlord will accept
On the plus side, next to my bay there is a stone pillar to hold the roof up and a chain will look around that… so all I have to do now is buy two almaxes (one around the pillar, the other around the bikes) and job done! :pinch:
Anyone know any good deals on almax chains at the moment?
Bargains to be had if you’re not set on Almax
http://www.pjbsecurity.co.uk/chains-only/
http://www.pjbsecurity.co.uk/new-untouchable-19mm-x-20m-security-chain-oxford-nemesis-padlock-disc-lock
Ah yeas I remember those…
Hmmm will take a look but looks like I’m going to have to cough up a substantial amount of dough one way or another 
I’ll take a picture tommorow, but by my work they have raised plant bedding pots with locking points for bicycles, looks like they are filled partway with concrete and then topped up with soil and plants. I’ve looking at these thinking that they were a nice idea and how simple to make up the equivalent at home.
Alternatively is there a flower bed near enough to the drive? Dig a decent size hole, get a steel loop/fixing point and fill it with post-crete but leave 6in under the soil level. Cover back up with soil and nobody will notice! No issue about moving it, get an angle grinder if need be and cut the loop off.
no need for picture… think I’m sorted now
Not a driveway but like a shared car park for the block of flats. Luckily I can get chains round the pillar so don’t need to do drilling… Have asked them if I can put a ground anchor in
Hold on Alex, weren’t you the one who had a bike nicked that was attached to a massive ball of concrete? They took the ball with them. Deja vu.
Nope… not me…
LOL!!! :laugh: