My son, almost 5 years old, occasionally gets to ride in my 914.
When he does, I install his Britax Frontier car seat. Obviously, there's no LATCH system, so I install it using the original 3-point (lap/shoulder) belts in my '74, with a locking clip to keep it tight. I also connect the top buckle on the car seat directly to the seat belt anchor on the inside of the targa bar, to keep the seat from tilting forward under braking (or in a crash).
Hopefully, I'll be driving with my son down to Scotty's shop this Saturday. That means about 2 hours each way on interstates, far longer than his previous rides and at highway speeds.
The Britax Frontier seat can convert to use it as a booster by removing the harness straps. My son is within the limits to use it as a booster (over 42", over 4 years old, and over 40lb).
So here's my question: What is safer, installing the seat with the seatbelt & a locking clip and using the harness, or removing the harness and just using the seat as a booster?
The harness is safer in general, but I'm not so comfortable with the jury-rigged nature of the install using a locking clip. At least as a booster, both the seat and the seat belt would be serving the purpose they were designed for.
To all the non-parents out there, I'm sure this is pretty Greek. But I need to reassure the wifee that I'm keeping our son as safe as possible...