Pretty sure that whole beach scene was just his brother with a CGI face, and then as you mentioned the car scene was most likely CGI. The scenes didn't look too bad really, and if you didn't know he was dead you might not even really notice. Was fairly obvious on the beach that they kept his face turned away most of the time though. And sappy as it was, I sort of liked the little tribute and "happily ever after" they gave him. I think it would have been tacky to kill him. Let him ride off into the sunset, I'm fine with that.
Some of the things I had to eye roll away were Statham apparently being able to not only find them anywhere BEFORE the God's Eye thing (I guess that road wasn't that well guarded if he could just drive up in his specially made super car that I'm sure didn't take weeks to make), Statham being a special forces badass and not instantly beating the fuck out of Vin Diesel (I'mma give my boy The Rock a pass since he's awesome and wouldn't go down easy...not enough Rock scenes though), the helicopter blowing shit up for like half an hour and no one doing anything except scrambling some jets that apparently were 3 minutes out...ten minutes ago. The list goes on, but as I said, you skip past them because we're only really there to see them do crazy shit with cars.
One thing that I was pleased with, however, was the lack of betrayal by Kurt Russell. They had that set up perfectly for him to fuck Dom over, but he didn't, he actually followed through on his promise and even got shot in the process. I was dreading the double-cross right then, and when it didn't happen I was fucking thrilled. That needs to happen more in movies like this, because the betrayal is way overused and almost expected. I'm glad they didn't go with it.