In Mercedes-Benz Group AG & Anor v Continental Teves UK Ltd & Ors  EWHC 1143 (Comm) Butcher J set aside permission for service out of the jurisdiction (against EU-incorporated defendants) in a follow-on damages claim following the European Commission’s Hydraulic Braking system cartel findings.
The UK parties are the anchor defendants. Pre-Brexit, the case against the non-UK defendants would have been brought under A8(1) Brussels Ia and the abuse threshold per CJEU CDC would have undoubtedly not been met.
The attractive UK discovery rules were mentioned by claimants as an important reason to anchor the case in the UK. On that point  the judge held per Spiliada‘s instruction [as a general rule, the court will not be deterred from granting a stay or refusing permission to serve out simply because the claimant will be deprived of a ‘legitimate personal or juridical advantage’, such as damages on a higher scale or a more generous disclosure regime, unless it is shown through cogent evidence that there is a risk that substantial justice will not be done in the natural forum] that substantial justice could not be done in Germany, if it was an available forum.
Butcher J overall  held that Germany is an available forum (in the case of the German defendants by reason of both A4 and A7(2) [locus delicti commissi] Brussels Ia, and in the case of the UK defendant by reason of the German forum connexitatis rules), with which the dispute has its closest and most real connexion, and which may be described as the natural forum for the present dispute.
The nature of the infringing conduct, causation and damage all overwhelmingly took place in Germany, witnesses largely have German as their mother tongue.  counsel for claimants makes an interesting point that matters of convenience ought not to weigh in favour of cartelists (essentially a nemo auditur application), however, the judge holds that ‘in relation to the matters which will be in issue, there has been no finding that Mercedes are right, or the Defendants wrong.
Further and importantly [albeit only as an additional argument: : ‘I should state, however, that I do not regard this factor as decisive. My conclusion on the natural forum would have been the same without it’],  the judge with respect to applicable law points to the disadvantage of England and Wales given the impossibility to refer to the CJEU
While the courts of England and Wales are obviously very used to applying EU law, and until recently did so as being directly applicable, it is the case that since the UK’s withdrawal from the EU, UK courts cannot make preliminary references to the CJEU in respect of questions of the interpretation of EU law. While the Claimants say that a reference to the CJEU in respect of the interpretation of a Settlement Decision would be unusual, it cannot be said to be unprecedented.
I am of the clear view that the forum with which the dispute has its closest and most real connexion is Germany, which is the natural forum for the dispute. The case has, in reality, very limited connexions with England and Wales, and it is not one, unlike very many which come before this court, where the parties have consensually chosen England and Wales as the forum for their disputes. The case has, by contrast, strong (and certainly much stronger) connexions with Germany.