I hear that a good alternative to the car-bonding is to put them in a laundry basked on top of the washing machine on spin cycle.  The idea is similar to to the car thing in that they should be a little frightened and seek comfort from each other.

I know somoene else put a dab of vanilla on each bun's head to encourage them to groom each other

I've heard about the vanilla too. I had read to put it under the bun's chin and bottom area to mask their scent.

I have heard it works well for some people

I tried the vanilla with my Pandora & (edited: Hareiette) and somebunny started screaming as they chased each other (like the horrifying death scream) and it scared the h*ll out of me. I think they got freaked since they couldn't smell it was the other!

Loopy-Lop

I agree with gravehearted's advice: To give them a break and start over.  Bunnies who have a nasty fight can keep grudges.

Starting slowly and do short bonding sessions.   You may have to start with a stress method before you put them in a neutral territory if they still want to kill each other when they see each other again.

When you do start again,use the kitchen strainer trick - it's  a trick that I learned from SaveABunny.com:  use a fine netted kitchen strainer  when you introduce them - to keep them separated while they can still sniff each other.  This way, if one goes nuts and tries to bite the other, they can't do any real damage and you can know right away whether you need take them on a car ride or put them through some sort of stress method first.

its so good to get support at the point when i'm giving up! i'll wait a few weeks then try a different way. i couldnt get them both in a box together when i tried but will give it another go. neither likes banana, beetroot is their vice but it might stain Blue's fur (not Lollo's cos he's black!) When you say vanilla, would it be the pure essence you use? My friend said her rabbits hated each other so much they couldnt even be in seperate cages near each other; in the end she took them to the local 'Pet's Corner' where they have large natural-environment type enclosures for various small animals. apparently the expert bloke took them away and when he came back they were loving each other. he'd rubbed them both with the same smell (dont know what though) and it worked a charm! do you think the fly-strike prevention spray would mask the bum-odour then i could use the vanilla on the heads to encourage petting?

The other thing i was thinking was to try bonding Lollo and Chino first as Chino is small and maybe would'nt be so intimidating to Lollo, plus they see more of each other (through a pen-panel) and so maybe are quite used to each other? she isnt spayed yet but he is neutered. is it a silly idea?

Loopylop - I am in the same-ish situation.  Don't give up!  I'm sure it can be done...

My bunnies are still seperate... i've started bonding twice and the 2nd time all was great but then 'dearest hubby' didn't watch them carefully (enough) and a fight broke out.  we keep them separate but the cages are together -although they are kept apart enough to stop damage through the bars and we have to put a mesh around them when one is out (Mable has bit Booboo's nose! and she was the one out!) So I've given them a break of about 3 weeks, and i'm going to start again soon.  We have let them out breifly together, most of the time its ok, but we can tell if tensions rise..and we can't take our eyes off them.

I think you have to be patience and not rush things..but it can be very frustrating and disapointing x

What seems to kick things off with mine is in the evenings, they both love to runs around binkying and skipping, but when they do this and they're both out it seems to annoy the other, and it turns into the 'death spiral' (god just saying it makes me scared) and thats it.  Its awful when they're gunning for each other..But i will keep trying and if i'm still here in 2 years saying the same thing then i will admit defeat, but not until!!

Taking them for a drive really helps mine, but so does putting them in the cardboard box and carrying it around x

thanks bunnybabe, its not that im glad that you're in the same boat but, well, i am kind of- it's good to know that people understand. its so gut-wrenching to see them fight when they are both so nice individually, and poor Lollo, he looked gutted that Blue had started on him! i will wait a few weeks and try again. thanks all for the support!