Here are directions from google maps.
1.Head
south on
Grant McConachie Waytoward
Service Rd3.8 km
2.Slight
right at
SW Marine Dr0.8 km
3.Continue onto
Granville St7.8 km
4.Slight
right at
Seymour St N1.4 km
5.Turn
left at
W Georgia St2.0 km
6.Continue onto
Stanley Park Causeway Rd2.1 km
7.Continue onto
HWY 1A/HWY 99/Lions Gate Bridge1.8 km
8.Take the ramp onto
Marine Dr1.0 km
9.Turn
right at
Taylor Way1.2 km
10.Turn
left onto the
HWY-1/BC-99 ramp to
Horseshoe Bay/Squamish/Whistler27 m
11.Keep
right at the fork to continue toward
BC-99/HWY-1 W0.1 km
12.Keep
left at the fork, follow signs for
BC-99/HWY-1 and merge onto
BC-99/HWY-1 W11.6 km
13.Take exit
1 for
MARINE Dr/BC-99 toward
Squamish/Whistler35 m
14.Merge onto
BC-99 N/Sea To Sky Hwy N
I don't know much about Vancouver car rentals though... Sorry. Hope that helps, I looked over all the directions and they all seem fine. A few of them might have traffic during rush hour.