Newbie to M Power

[A8 PMJ]

Hello you knowledgeable lot.
Just bought myself a '65 plate F10 M5, with the Competition Pack.
The sale was conducted over the internet and the first time I saw it in the flesh was yesterday, when it was delivered.
Fabulous condition and low mileage with a FBMWSH.
It sounded loud coming off the transporter and I found out why later.
It has Cat back Eisenmann exhaust. I have yet to look underneath, but I think it is the Non resonator system.
I live on a very quiet estate, so here are my questions:

This car was sold to me as an unmodified car, if the garage are reluctant to put it right, can I reject the car?
If not, I have heard of a cold start delete, can this be done on my car and who could do this? To help with the noise in the morning.
I also think it has had an iffy Remap, because on the overrun from above 3000rpm, it pops and bangs so badly
you would think a Spitfire has just landed. Ridiculously loud.
I love the car, it looks gorgeous and don't want to reject it. Do you think the garage should fix it?
Sorry my first post was a biggie.
Cheers Pat

[A8 PMJ]

Thank you Gents. I will have that conversation.

[A8 PMJ]

Thank you

[A8 PMJ]

Hi everyone, I had the car checked today by a BMW Master Technician.
Not only has the car got a full Eisenmann exhaust system, but the cats have been removed too
and the bellows have been removed and the exhaust butterflies have been wired open.
He also confirmed it has been remapped, badly.
He also said without the cats it would fail an MOT, so it brings into doubt the validity of the
years MOT, I have on the car.

Please can I have your input, as to what to do, bearing in mind, it is the best condition M5
he has seen in a long time.
Should I try some old fashioned "horse trading" or reject it out of hand?
Pat

[A8 PMJ]

Thank you everyone. I appreciate your input.

I have emailed the dealer with my concerns and await his reply.

It is such a shame a previous owner was such a "Gary Boy".

The dealer has asked for me to give a review on his own site and Autotrader.

That could be fun!!!!!

[A8 PMJ]

I am. Please tell me more. Pat

[A8 PMJ]

Boozy, thank you for that. I am pleased the car that you wanted. I hope to do the same.
Pat

[A8 PMJ]

I have given the garage the opportunity to put the car back to stock and re do the MOT.

I will then have the car inspected, independently, to ensure this is done, but have reserved the right to reject it
if it is not done to my satisfaction.

[A8 PMJ]

Thank you both for your input.