I've got a flight to DFW (from LHR) on Monday 16th Jan but I need to get to Austin (Downtown Marriott). I chose to go to DFW because I could get BA Club World for ~£2000 whereas business class to Austin was ~£7000.

Outbound I land in DFW at 3:25pm. I'm debating whether to book on a connecting flight and, if so, at what time. Alternatively I could just get a car service all the way for ~$300. Would that be a better option?

On the way back (on Saturday 21st Jan) I need to connect with a flight departing 3:43pm from DFW (actually via BOS). I'm even more tempted to get a car back becuase it is more reliable than flying. I'd even consider a bus (but it doesn't seem that buses go from Austin straight to the airport). Any thoughts?