Hi all, I’m the owner of a 2010 A5. It’s in remarkable condition except for the underneath and even that’s not too bad. I’d love to get under there and sort some of the surface rust but I can’t get under there.  Car is too low for ramps at the front due to bumper. I can reverse onto ramps but access is still very difficult. 
any help or suggestions please ?

Thank you

Welcome Anthony and thanks for joining. 
Without being dismissive of your problem, if you can’t (easily) get under the car to do the preparation, then the only option is to get someone to do it for you. 
I would start to ask for local recommendations at established valeters. These people will generally know who to go to. 
In case it helps, I’ve had good reports about an underbody treatment called Lanoguard. 
Let us know how you get on Anthony.

Kind regards,

Gareth.

Thank you

Axle stands would do the job, but you would need to know where to place them for safe access underneath. Even more crucial is knowing how to jack the car up without risk of injury to yourself or damage to the car in order to place the axle stands. If you don't have that expertise then pay somebody to do the job.

Thanks cliff 👍