I highly doubt the finance company would allow you to, it's their car and there's usually clauses in the T&Cs.
There has been people pulled up about it before.
I guess it's if your dealer shops you or not. There is a lot of people doing it.
It's the finance companies car when purchasing through HP too, lots of people mod their cars, just need to be savvy when you do it.
My two previous cars have both been modified, Focus ST quite heaviy - bought through HP. Golf R just a remap - bought through PCP.
Yup, pretty much all finance is secured on the car making it the car the finance companies' property.
There will come a time when dealers are forced to check for remaps and the like, it's actually quite fair too.
Quite a lot of people are going to buy these cars at 3 years old, extend the warranty, then get knocked back later on as there is codes triggered for remapping, even after removed.
There's also going to people on finance/lease deals going to have a big mechanical failure(I've seen and read about quite a few Rs going bang, a few M135/235i too) and get refused their claim. They'll be left with huge bills that they will likely not be able to afford.
There was a guy who started a thread on PH after VW knocked back his warranty claim after his engine went bang. He gave the story he hadn't remapped it, although VW said it had been and then removed, so he was saying if it had been remapped, it must have been without his knowledge. The car had 40 miles on the clock when he picked it up and that was his argument.
Then someone kindly linked videos on his Youtube channel racing down the quarter mile at Crail stating the car's tune. They also linked the times that were consistent with a remapped car and pointed out his relationship with one of the big VAG tuners.
The tuner had claimed maps could be removed without detection.
His Youtube videos were deleted, his times disappeared from Crail's website and he never posted again. It would have been good to have heard the outcome, but he was clearly caught out badly.
I really struggle with the theory of buying a brand new car on finance, paying all the premium for warranties and cover, then instantly risking the warranty and putting the finance at risk with tuning.
Surely if you want to head down the modifying route with extensive changes, buying something used would be wiser?