Sure, there is no reason why you can't use aftermarket speakers, so long as you match the impedence of the factory units.
But for me personally I don't like cutting wires, or cutting/drilling metal in these cars, any modification should be reversible. That's just my philosophy. You won't find an aftermarket speaker that is a direct fit, you will need to cut wires or make other changes that are going to be kind of permanent.
Plus my only experience with using aftermarket speakers with factory audio systems was less than encouraging, it just did not sound as good as factory speakers...
The B&W speakers from the 2008-2011 Jag XF are freakin awesome.
Attachment 127238
That's a factory "Meridian" speaker on the left, Bowers & Wilkins on the right, you can see the difference, let alone hear it!
I suppose a TPMS retrofit would be possible in the DS, same like we did in the Freelander2 & Disco4.
But to be honest the current tally of TPMS retrofit vs. TPMS disable has now swung over to the disable side.
5x TPMS systems retrofitted, 7x TPMS systems disabled. They are a real pain in the backside when they decide to stop working....
I've never been to South America, buy me a ticket and i'll come visit!